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2024 Volume 39 Issue 3
2024, 39(3): 1-4
doi: 10.3866/PKU.DXHX202306084
Abstract:
This paper provides a brief overview of the blended learning approach in structural chemistry at Peking University, as well as details on the small-group discussion sessions focused on the topic of “lattice structures and properties of crystals”.
This paper provides a brief overview of the blended learning approach in structural chemistry at Peking University, as well as details on the small-group discussion sessions focused on the topic of “lattice structures and properties of crystals”.
2024, 39(3): 5-17
doi: 10.3866/PKU.DXHX202308107
Abstract:
Using Si crystals as an illustrative example, an integrated approach to teaching crystallography with X-ray/electron diffraction and TEM/STM imaging, including the principles, technologies and results, was presented to help students building up the links among different crystallographic methods and technologies for structure characterization, so that they have a complete and integrated understanding of crystallographic concepts, theories and the results from different technologies.
Using Si crystals as an illustrative example, an integrated approach to teaching crystallography with X-ray/electron diffraction and TEM/STM imaging, including the principles, technologies and results, was presented to help students building up the links among different crystallographic methods and technologies for structure characterization, so that they have a complete and integrated understanding of crystallographic concepts, theories and the results from different technologies.
2024, 39(3): 18-22
doi: 10.3866/PKU.DXHX202304003
Abstract:
Crystal structures are important teaching content in structural chemistry courses, which contains many knowledge points, abstract concepts and fundamental theories. This paper explores the descriptions and connotations of several basic concepts of crystal structures, including the lattice, crystal lattice, structural motif, and unit cell. The goal is to help students clarify their understanding of the basic concepts of crystallographic theory.
Crystal structures are important teaching content in structural chemistry courses, which contains many knowledge points, abstract concepts and fundamental theories. This paper explores the descriptions and connotations of several basic concepts of crystal structures, including the lattice, crystal lattice, structural motif, and unit cell. The goal is to help students clarify their understanding of the basic concepts of crystallographic theory.
2024, 39(3): 23-28
doi: 10.3866/PKU.DXHX202303003
Abstract:
The properties of materials are determined by their structures. The research on structures is the basis and guidance of modern chemistry, material and biology, and the structure determination is an essential skill and method for scholars and students. X-ray diffraction is the most common method to investigate the structures of matter. However, current X-ray crystallography courses offered by Chinese universities were hindered by the limited capacities, the overemphasis on theories and the lack of practices, which cannot fulfill the need of students especially those who focused their research on non-crystallographic areas. Consequently, students find it difficult to obtain efficient and accurate support and guidance from existing resources and instructors, leaving a large gap between the requirement and supply when facing problems in X-ray structure determination. In this work, the current domestic situation of the popularization of X-ray crystallography was investigated. To improve the capabilities of X-ray structure determination for the teachers and students, the current teaching methods and contents of X-ray crystallography courses need to be reformed to be more practical to meet the needs of non-crystallographic users. Detailed suggestions were clarified for the improvement from three aspects: knowledge, skill, and confidence, and assigned the practical X-ray crystallography into three section: the principle of X-ray, introduction to crystallography, skills for X-ray diffraction data collection and structure refinement. We also need to improve students’ confidence during processing the structure determination.
The properties of materials are determined by their structures. The research on structures is the basis and guidance of modern chemistry, material and biology, and the structure determination is an essential skill and method for scholars and students. X-ray diffraction is the most common method to investigate the structures of matter. However, current X-ray crystallography courses offered by Chinese universities were hindered by the limited capacities, the overemphasis on theories and the lack of practices, which cannot fulfill the need of students especially those who focused their research on non-crystallographic areas. Consequently, students find it difficult to obtain efficient and accurate support and guidance from existing resources and instructors, leaving a large gap between the requirement and supply when facing problems in X-ray structure determination. In this work, the current domestic situation of the popularization of X-ray crystallography was investigated. To improve the capabilities of X-ray structure determination for the teachers and students, the current teaching methods and contents of X-ray crystallography courses need to be reformed to be more practical to meet the needs of non-crystallographic users. Detailed suggestions were clarified for the improvement from three aspects: knowledge, skill, and confidence, and assigned the practical X-ray crystallography into three section: the principle of X-ray, introduction to crystallography, skills for X-ray diffraction data collection and structure refinement. We also need to improve students’ confidence during processing the structure determination.
2024, 39(3): 29-35
doi: 10.3866/PKU.DXHX202308060
Abstract:
X-ray diffraction is a pivotal technique for material structure analysis, playing a fundamental role in materials chemistry. In light of the continuous discovery of novel materials, advanced X-ray diffraction methods have emerged at the forefront of materials chemistry. This paper introduces a teaching reform incorporating three advanced X-ray techniques into materials chemistry instruction: high-pressure synchrotron X-ray diffraction, micro-focus X-ray diffraction, and X-ray pair distribution function analysis. We anticipate that such a teaching reform will empower students to deepen their grasp of X-ray diffraction techniques, broaden their academic horizons, and refine their problem-solving skills.
X-ray diffraction is a pivotal technique for material structure analysis, playing a fundamental role in materials chemistry. In light of the continuous discovery of novel materials, advanced X-ray diffraction methods have emerged at the forefront of materials chemistry. This paper introduces a teaching reform incorporating three advanced X-ray techniques into materials chemistry instruction: high-pressure synchrotron X-ray diffraction, micro-focus X-ray diffraction, and X-ray pair distribution function analysis. We anticipate that such a teaching reform will empower students to deepen their grasp of X-ray diffraction techniques, broaden their academic horizons, and refine their problem-solving skills.
2024, 39(3): 36-42
doi: 10.3866/PKU.DXHX202308029
Abstract:
In the teaching of Structural Chemistry, the diversity, complexity and abstract nature of crystal structures augment the instructional challenges. This paper delineates the author’s pedagogical approach in teaching practice, predicated on the symmetry of crystal structures, following a concrete-abstract-concrete thematic thread, and centering on “extracting commonality–delving into typicals–deriving individuality” to expand the educational methodology in construct a knowledge graph of crystal structures. The specific approach commences with the close-packing of equal-diameter spheres and their void types/distributions as the commonality starting point, progresses through void-filling models to ascertain typical crystal structures, and employs substitution/addition/removal/derivation techniques to establish the crystal structures of specific substances with diversity, thereby forming a knowledge graph with intuitive and contextual relationships. It can deepen students’ comprehension of the commonality and individuality in crystal structure education, achieving the purpose of knowledge understanding and transferable application.
In the teaching of Structural Chemistry, the diversity, complexity and abstract nature of crystal structures augment the instructional challenges. This paper delineates the author’s pedagogical approach in teaching practice, predicated on the symmetry of crystal structures, following a concrete-abstract-concrete thematic thread, and centering on “extracting commonality–delving into typicals–deriving individuality” to expand the educational methodology in construct a knowledge graph of crystal structures. The specific approach commences with the close-packing of equal-diameter spheres and their void types/distributions as the commonality starting point, progresses through void-filling models to ascertain typical crystal structures, and employs substitution/addition/removal/derivation techniques to establish the crystal structures of specific substances with diversity, thereby forming a knowledge graph with intuitive and contextual relationships. It can deepen students’ comprehension of the commonality and individuality in crystal structure education, achieving the purpose of knowledge understanding and transferable application.
2024, 39(3): 43-57
doi: 10.3866/PKU.DXHX202307050
Abstract:
A comprehensive 8-hour chemical experiment was devised around the single crystal-to-single crystal (SCSC) transformation, an emerging method in solid-phase inorganic synthesis. By employing a direct additive process technology, the green complexes (H3O)[K(15C5)2][CuCl4] (1) were synthesized in both powder and macro-single crystal forms. Upon temperature induction, complex 1 transitions to the red complex [K(15C5)2][CuCl3] (2), a shift attributed to the restricted dimerization of [CuCl3]- resulting from steric repulsion effects in the solid phase. Notably, complex 2 can revert back to complex 1 when exposed to hydrochloric steam through an SCSC transformation. This SCSC transformation between complexes 1 and 2 is vividly demonstrated on filter paper, showcasing dynamic color changes, either as texts or drawings. This rapid and visually engaging process is poised to spark students’ curiosity. Furthermore, learners can bridge theory with practice, recognizing that the distinct colors of the two complexes arise from varying coordination numbers of copper (II), grounded in the crystal field theory of inorganic chemistry. Characterization of the complexes was achieved using single crystal X-ray diffraction, powder X-ray diffraction, UV-visible spectroscopy, and Fourier transform infrared spectroscopy, confirming the differentiation of the complexes and the successful SCSC transformation. This aspect of the experiment allows students to hone their skills with the Cambridge crystal structure database and enhance their data analysis capabilities, fostering proficiency in operating large-scale instruments safely and accurately. With its streamlined design, modular teaching approach, and cost-effective reagents, this experiment is primed for integration into undergraduate curriculum for chemistry and related disciplines.
A comprehensive 8-hour chemical experiment was devised around the single crystal-to-single crystal (SCSC) transformation, an emerging method in solid-phase inorganic synthesis. By employing a direct additive process technology, the green complexes (H3O)[K(15C5)2][CuCl4] (1) were synthesized in both powder and macro-single crystal forms. Upon temperature induction, complex 1 transitions to the red complex [K(15C5)2][CuCl3] (2), a shift attributed to the restricted dimerization of [CuCl3]- resulting from steric repulsion effects in the solid phase. Notably, complex 2 can revert back to complex 1 when exposed to hydrochloric steam through an SCSC transformation. This SCSC transformation between complexes 1 and 2 is vividly demonstrated on filter paper, showcasing dynamic color changes, either as texts or drawings. This rapid and visually engaging process is poised to spark students’ curiosity. Furthermore, learners can bridge theory with practice, recognizing that the distinct colors of the two complexes arise from varying coordination numbers of copper (II), grounded in the crystal field theory of inorganic chemistry. Characterization of the complexes was achieved using single crystal X-ray diffraction, powder X-ray diffraction, UV-visible spectroscopy, and Fourier transform infrared spectroscopy, confirming the differentiation of the complexes and the successful SCSC transformation. This aspect of the experiment allows students to hone their skills with the Cambridge crystal structure database and enhance their data analysis capabilities, fostering proficiency in operating large-scale instruments safely and accurately. With its streamlined design, modular teaching approach, and cost-effective reagents, this experiment is primed for integration into undergraduate curriculum for chemistry and related disciplines.
2024, 39(3): 58-62
doi: 10.3866/PKU.DXHX202304014
Abstract:
Macrocyclic receptors have served as the principal tools of supramolecular chemistry because of their innate molecular recognition and complexation capabilities. They have also increased research interest in modern supramolecular chemistry because of their practical applications. Leaning towerarenes, a new family of synthetic macrocycles, have various applications in crystal engineering and other related fields owing to their excellent solubility and crystallization, flexible backbone, and superior host-guest properties. In this paper, we summarize the applications of leaning towerarenes from the perspective of crystal engineering. Particular attention is paid to the correlation between their structural features and supramolecular functions. We hope this will stimulate students’ interest in crystal chemistry and beyond.
Macrocyclic receptors have served as the principal tools of supramolecular chemistry because of their innate molecular recognition and complexation capabilities. They have also increased research interest in modern supramolecular chemistry because of their practical applications. Leaning towerarenes, a new family of synthetic macrocycles, have various applications in crystal engineering and other related fields owing to their excellent solubility and crystallization, flexible backbone, and superior host-guest properties. In this paper, we summarize the applications of leaning towerarenes from the perspective of crystal engineering. Particular attention is paid to the correlation between their structural features and supramolecular functions. We hope this will stimulate students’ interest in crystal chemistry and beyond.
2024, 39(3): 63-69
doi: 10.3866/PKU.DXHX202302060
Abstract:
Being the professional visual software for the refinement of small molecular crystal structure, ShelXle has a large number of users among college groups. Due to the lack of literature reports on the using and research of ShelXle at home and abroad nowadays, many teachers and students were puzzled on how to deal with the problems encountered in the process of refinement using ShelXle. In this paper, the development backgrounds, the basic and special functions and the using method of ShelXle are presented in detail. Combined with several cases and compared with other visual software, its technical superiorities in the refinement of small molecular crystal structures were analyzed, and some suggestions about enhancing its refinement effect were also illustrated.
Being the professional visual software for the refinement of small molecular crystal structure, ShelXle has a large number of users among college groups. Due to the lack of literature reports on the using and research of ShelXle at home and abroad nowadays, many teachers and students were puzzled on how to deal with the problems encountered in the process of refinement using ShelXle. In this paper, the development backgrounds, the basic and special functions and the using method of ShelXle are presented in detail. Combined with several cases and compared with other visual software, its technical superiorities in the refinement of small molecular crystal structures were analyzed, and some suggestions about enhancing its refinement effect were also illustrated.
2024, 39(3): 70-77
doi: 10.3866/PKU.DXHX202311100
Abstract:
Packing-filling model is an efficient way to understand the crystal structure. The representation of the distribution of the atoms and interstices in the packing-filling model is called the symbolic representation of the packing-filling model. The symbolic representation of the packing-filling model in the crystal structure is systematically elaborated, and various application methods of the symbolic representation are introduced in detail to deepen the understanding of the crystal structure.
Packing-filling model is an efficient way to understand the crystal structure. The representation of the distribution of the atoms and interstices in the packing-filling model is called the symbolic representation of the packing-filling model. The symbolic representation of the packing-filling model in the crystal structure is systematically elaborated, and various application methods of the symbolic representation are introduced in detail to deepen the understanding of the crystal structure.
2024, 39(3): 78-85
doi: 10.3866/PKU.DXHX202309004
Abstract:
During the crystallization process of certain racemic compounds, spontaneous resolution can lead to distinctive external appearances of enantiomeric crystal forms. This article offers a comprehensive overview and delineates four methods for identification, namely, examining hemihedral faces, assessing macromorphology, employing circular polarization, and analyzing surface topography. These identification techniques serve as invaluable tools and viewpoints for studying the crystallization behavior of chiral compounds, holding significant potential across diverse applications in pharmaceutical production, materials science, and chemical synthesis.
During the crystallization process of certain racemic compounds, spontaneous resolution can lead to distinctive external appearances of enantiomeric crystal forms. This article offers a comprehensive overview and delineates four methods for identification, namely, examining hemihedral faces, assessing macromorphology, employing circular polarization, and analyzing surface topography. These identification techniques serve as invaluable tools and viewpoints for studying the crystallization behavior of chiral compounds, holding significant potential across diverse applications in pharmaceutical production, materials science, and chemical synthesis.
2024, 39(3): 86-93
doi: 10.3866/PKU.DXHX202308113
Abstract:
The field of crystal engineering has evolved from the amalgamation of supramolecular self-assembly, bridging the interdisciplinary domains of crystallography, materials science, and synthetic chemistry. The crystal engineering for supramolecular chirality constitutes a specialized branch within this field, utilizing the principles and techniques of crystal engineering to design chiral supramolecular building blocks, create chiral supramolecular crystalline materials, and investigate potential applications in enantiomer-selective recognition, separation, and catalysis.
The field of crystal engineering has evolved from the amalgamation of supramolecular self-assembly, bridging the interdisciplinary domains of crystallography, materials science, and synthetic chemistry. The crystal engineering for supramolecular chirality constitutes a specialized branch within this field, utilizing the principles and techniques of crystal engineering to design chiral supramolecular building blocks, create chiral supramolecular crystalline materials, and investigate potential applications in enantiomer-selective recognition, separation, and catalysis.
2024, 39(3): 94-102
doi: 10.3866/PKU.DXHX202310035
Abstract:
This paper provides a concise overview of three commonly employed methods for the determination of crystal structures from powder diffraction data, each exemplified with a specific case study. The first method is the single-crystal-like direct methods, leveraging reciprocal space information to construct the structure model. The second approach involves simulated annealing, which performs a global optimization of randomly generated models in real space to identify the structure. The third is the charge flipping method in which modifications to structure factors in reciprocal space and charge densities in real space are made, leading to the determination of the structure model through Fourier cycling switching back and forth between the two spaces. The presented examples are Ba3BPO7, MgSO4·2H2O and MgSO4·2.5H2O, respectively.
This paper provides a concise overview of three commonly employed methods for the determination of crystal structures from powder diffraction data, each exemplified with a specific case study. The first method is the single-crystal-like direct methods, leveraging reciprocal space information to construct the structure model. The second approach involves simulated annealing, which performs a global optimization of randomly generated models in real space to identify the structure. The third is the charge flipping method in which modifications to structure factors in reciprocal space and charge densities in real space are made, leading to the determination of the structure model through Fourier cycling switching back and forth between the two spaces. The presented examples are Ba3BPO7, MgSO4·2H2O and MgSO4·2.5H2O, respectively.
2024, 39(3): 103-107
doi: 10.3866/PKU.DXHX202307051
Abstract:
Within the framework of materials chemistry education, this study incorporates indium antimonide twin crystal nanostructures and associated structural characterization data from laboratory experiments into the teaching curriculum. Additionally, we employ VESTA software to simulate the indium antimonide twin crystal nanostructure model. By using VESTA software in real-time during lessons, we vividly present three-dimensional twin crystal structures from various angles and display perspectives. This integrated model, combining “theoretical knowledge explanation + software operation demonstration + scientific research results case”, not only enhances students’ comprehension of twin crystal structures but also ignites their enthusiasm for learning. Moreover, it fosters their ability to use scientific tools in practical problem-solving, bridging the gap between classroom instruction and scientific research exploration.
Within the framework of materials chemistry education, this study incorporates indium antimonide twin crystal nanostructures and associated structural characterization data from laboratory experiments into the teaching curriculum. Additionally, we employ VESTA software to simulate the indium antimonide twin crystal nanostructure model. By using VESTA software in real-time during lessons, we vividly present three-dimensional twin crystal structures from various angles and display perspectives. This integrated model, combining “theoretical knowledge explanation + software operation demonstration + scientific research results case”, not only enhances students’ comprehension of twin crystal structures but also ignites their enthusiasm for learning. Moreover, it fosters their ability to use scientific tools in practical problem-solving, bridging the gap between classroom instruction and scientific research exploration.
2024, 39(3): 108-117
doi: 10.3866/PKU.DXHX202306005
Abstract:
This paper explores the use of the Python language and scientific computing libraries to visualize the wave functions and electron clouds of common hydrogen atomic s and p orbitals in structural chemistry. Multiple scripts have been developed in this process, employing data processing and various generation algorithms to achieve the visualization of wave functions and electron clouds. The aim is to guide students in a comprehensive study and understanding of the physical significance of wave functions and electron clouds. This approach enhances students’ abilities for independent thinking and active learning.
This paper explores the use of the Python language and scientific computing libraries to visualize the wave functions and electron clouds of common hydrogen atomic s and p orbitals in structural chemistry. Multiple scripts have been developed in this process, employing data processing and various generation algorithms to achieve the visualization of wave functions and electron clouds. The aim is to guide students in a comprehensive study and understanding of the physical significance of wave functions and electron clouds. This approach enhances students’ abilities for independent thinking and active learning.
2024, 39(3): 118-121
doi: 10.3866/PKU.DXHX202311043
Abstract:
The method of constructing 47 crystal simplex models using Diamond software and its application in teaching were introduced.
The method of constructing 47 crystal simplex models using Diamond software and its application in teaching were introduced.
2024, 39(3): 122-131
doi: 10.3866/PKU.DXHX202309008
Abstract:
Inorganic chemistry serves as a fundamental subject in university chemistry disciplines. To address the issues of fragmented knowledge points, monotonous teaching method and insufficient training in disciplinary thinking, we explored a “stepped-task driven + multi-dimensional output” model. Focusing on intermolecular forces as a case study, this approach incorporates diverse and interactive evaluation methods, including the use of Rubrics assessment scales. The practical implementation of this teaching model has shown promising outcomes, effectively facilitating personalized student development, enhancing active engagement, strengthening professional identification and cultivating disciplinary literacy.
Inorganic chemistry serves as a fundamental subject in university chemistry disciplines. To address the issues of fragmented knowledge points, monotonous teaching method and insufficient training in disciplinary thinking, we explored a “stepped-task driven + multi-dimensional output” model. Focusing on intermolecular forces as a case study, this approach incorporates diverse and interactive evaluation methods, including the use of Rubrics assessment scales. The practical implementation of this teaching model has shown promising outcomes, effectively facilitating personalized student development, enhancing active engagement, strengthening professional identification and cultivating disciplinary literacy.
2024, 39(3): 132-137
doi: 10.3866/PKU.DXHX202309089
Abstract:
Analytical Chemistry course is a core professional course for chemistry majors and other related majors. Achieving the objectives of this course is crucial for the cultivation of professional talent. Effective implementation of teaching reform and design plays a significant role in enhancing the achievement of curriculum objectives. This paper aims to deepen the curriculum reform based on current implementation issues, and establish a triadic-driven curriculum reform and design model. This model integrates a learning community involving both teachers and students, promotes a seamless online and offline integration, emphasizes curriculum-based ideological and political education, pursues excellence in curriculum elements of profoundness-innovation-challenging, and continuously integrates Outcome-Based Education (OBE) philosophy. Thus, a curriculum reform model known as “unified body, dual-line integration, and triadic drive” has been constructed.
Analytical Chemistry course is a core professional course for chemistry majors and other related majors. Achieving the objectives of this course is crucial for the cultivation of professional talent. Effective implementation of teaching reform and design plays a significant role in enhancing the achievement of curriculum objectives. This paper aims to deepen the curriculum reform based on current implementation issues, and establish a triadic-driven curriculum reform and design model. This model integrates a learning community involving both teachers and students, promotes a seamless online and offline integration, emphasizes curriculum-based ideological and political education, pursues excellence in curriculum elements of profoundness-innovation-challenging, and continuously integrates Outcome-Based Education (OBE) philosophy. Thus, a curriculum reform model known as “unified body, dual-line integration, and triadic drive” has been constructed.
2024, 39(3): 138-142
doi: 10.3866/PKU.DXHX202309015
Abstract:
The construction of emerging engineering education is an important measure to meet the new demands of national strategic development and a new starting point for reform and innovation in engineering education. The Applied Chemistry program at China University of Geosciences (Wuhan) leverages the advantages of geology, resources, and environmental disciplines. Through measures such as establishing industry-education integration pathways, leading with exemplary courses, and cultivating practical experiences, the program has explored and practiced an integrated education model that meets the requirements of talent cultivation under the background of emerging engineering education, specifically in the field of applied chemistry.
The construction of emerging engineering education is an important measure to meet the new demands of national strategic development and a new starting point for reform and innovation in engineering education. The Applied Chemistry program at China University of Geosciences (Wuhan) leverages the advantages of geology, resources, and environmental disciplines. Through measures such as establishing industry-education integration pathways, leading with exemplary courses, and cultivating practical experiences, the program has explored and practiced an integrated education model that meets the requirements of talent cultivation under the background of emerging engineering education, specifically in the field of applied chemistry.
2024, 39(3): 143-148
doi: 10.3866/PKU.DXHX202309071
Abstract:
Focusing on the goal of innovative talent cultivation centered on student development, we have, over years of ongoing educational reform and exploration, proposed a modular analytical chemistry experiment teaching approach based on the “comprehensive + exploratory” experiments. The undergraduates are required to independently design experimental protocols for the problems discovered during the comprehensive experiments, and then conduct individual experiment. Meanwhile, the graduate seminar mode is integrated into the experimental teaching, through the inclusion of an experimental protocol defense, finally achieving the “one student, one plan” educational strategy. Since the implementation of this teaching method, significant improvements have been observed. The approach not only stimulates students’ potential interest in learning and experiment, but also enhances integrated practical skills including experimental reasoning and knowledge application. Furthermore, it paves the way for cultivating divergent thinking and innovative capabilities, receiving widespread acclaim and endorsement.
Focusing on the goal of innovative talent cultivation centered on student development, we have, over years of ongoing educational reform and exploration, proposed a modular analytical chemistry experiment teaching approach based on the “comprehensive + exploratory” experiments. The undergraduates are required to independently design experimental protocols for the problems discovered during the comprehensive experiments, and then conduct individual experiment. Meanwhile, the graduate seminar mode is integrated into the experimental teaching, through the inclusion of an experimental protocol defense, finally achieving the “one student, one plan” educational strategy. Since the implementation of this teaching method, significant improvements have been observed. The approach not only stimulates students’ potential interest in learning and experiment, but also enhances integrated practical skills including experimental reasoning and knowledge application. Furthermore, it paves the way for cultivating divergent thinking and innovative capabilities, receiving widespread acclaim and endorsement.
2024, 39(3): 149-157
doi: 10.3866/PKU.DXHX202309077
Abstract:
Basic Chemistry is a mandatory course for medical undergraduates, serving as the foundation for their subsequent specialized medical studies and professional endeavors. A major obstacle in engaging students’ learning interests lies in their inability to perceive the connection between medicine and chemistry. To address this challenge and stimulate student involvement, problem-based learning teaching has been incorporated into the curriculum design. Taking the teaching of osmotic pressure of solutions as an example, various scenarios closely related to daily life or medical practice are introduced to stimulate students’ interest in learning. The teaching design also encourages them to explore the subject matter through problem-solving, effectively improving their abilities in independent thinking, analogical reasoning, and integrated comprehension. Additionally, the seamless integration of ideological and political elements within the course contributes to nurturing patriotic sentiments, ethnic pride, and good medical ethics among the students.
Basic Chemistry is a mandatory course for medical undergraduates, serving as the foundation for their subsequent specialized medical studies and professional endeavors. A major obstacle in engaging students’ learning interests lies in their inability to perceive the connection between medicine and chemistry. To address this challenge and stimulate student involvement, problem-based learning teaching has been incorporated into the curriculum design. Taking the teaching of osmotic pressure of solutions as an example, various scenarios closely related to daily life or medical practice are introduced to stimulate students’ interest in learning. The teaching design also encourages them to explore the subject matter through problem-solving, effectively improving their abilities in independent thinking, analogical reasoning, and integrated comprehension. Additionally, the seamless integration of ideological and political elements within the course contributes to nurturing patriotic sentiments, ethnic pride, and good medical ethics among the students.
2024, 39(3): 158-166
doi: 10.3866/PKU.DXHX202308101
Abstract:
“Quantitative Analytical Chemistry” is a compulsory foundational course for students in relevant majors at agricultural and forestry universities. It is offered in various fields such as agriculture, forestry, animal science, biology, food science, environmental science, and biology. Under the background of the construction of “new agricultural science”, this paper addresses several pain points in the teaching process, including the misalignment of limited teaching hours with extensive course content, lack of integration between the course’s subject matter and the concept of “New Agricultural Sciences”, disconnection between teaching content and ideological and political education, monotony in teaching modes and evaluation methods, and scarcity of teaching resources. The paper proposes solutions and suggestions in terms of teaching content, teaching design, teaching modes, teaching resources, ideological and political education, and evaluation methods, aiming to provide a reference for the reform of the “Quantitative Analytical Chemistry” course.
“Quantitative Analytical Chemistry” is a compulsory foundational course for students in relevant majors at agricultural and forestry universities. It is offered in various fields such as agriculture, forestry, animal science, biology, food science, environmental science, and biology. Under the background of the construction of “new agricultural science”, this paper addresses several pain points in the teaching process, including the misalignment of limited teaching hours with extensive course content, lack of integration between the course’s subject matter and the concept of “New Agricultural Sciences”, disconnection between teaching content and ideological and political education, monotony in teaching modes and evaluation methods, and scarcity of teaching resources. The paper proposes solutions and suggestions in terms of teaching content, teaching design, teaching modes, teaching resources, ideological and political education, and evaluation methods, aiming to provide a reference for the reform of the “Quantitative Analytical Chemistry” course.
2024, 39(3): 167-173
doi: 10.3866/PKU.DXHX202308116
Abstract:
In the current context of rapid development of “Intelligent Chemical Engineering”, as one of the core courses of chemical engineering, the teaching of physical chemistry should not only respond to the knowledge and skill requirements of chemical engineering professionals in the field of intelligent chemical engineering, but also actively explore innovative teaching methods and approaches, incorporating the latest technological achievements of intelligent chemical engineering into the teaching process. By further optimizing the content of the curriculum and introducing advanced computer-aided teaching and simulation experiments, the teaching effectiveness can be enhanced, and students’ practical abilities and innovative awareness can be strengthened, thus cultivating their ability to adapt to the development of intelligent chemical engineering.
In the current context of rapid development of “Intelligent Chemical Engineering”, as one of the core courses of chemical engineering, the teaching of physical chemistry should not only respond to the knowledge and skill requirements of chemical engineering professionals in the field of intelligent chemical engineering, but also actively explore innovative teaching methods and approaches, incorporating the latest technological achievements of intelligent chemical engineering into the teaching process. By further optimizing the content of the curriculum and introducing advanced computer-aided teaching and simulation experiments, the teaching effectiveness can be enhanced, and students’ practical abilities and innovative awareness can be strengthened, thus cultivating their ability to adapt to the development of intelligent chemical engineering.
2024, 39(3): 174-177
doi: 10.3866/PKU.DXHX202309052
Abstract:
The electrochemical principles course is a commonly offered course in disciplines such as chemistry, chemical engineering, materials science, environmental engineering, and renewable energy. The commonly used textbooks for this course are often written based on “disciplinary thinking,” which does not align with students’ cognitive laws. Based on the “cognitive laws,” the author has reconstructed the chapter on electron transfer step kinetics in the electrochemical principles course. This reconstruction will contribute to the achievement of students’ objectives and reflect the thinking and connotation of the construction of new engineering disciplines.
The electrochemical principles course is a commonly offered course in disciplines such as chemistry, chemical engineering, materials science, environmental engineering, and renewable energy. The commonly used textbooks for this course are often written based on “disciplinary thinking,” which does not align with students’ cognitive laws. Based on the “cognitive laws,” the author has reconstructed the chapter on electron transfer step kinetics in the electrochemical principles course. This reconstruction will contribute to the achievement of students’ objectives and reflect the thinking and connotation of the construction of new engineering disciplines.
2024, 39(3): 178-190
doi: 10.3866/PKU.DXHX202309087
Abstract:
In response to challenges such as homogeneity of assessment methods and low student engagement in current Chemical Engineering Principle Experimental Course teaching, this study introduces virtual simulation and “Internet +” technologies into the curriculum. A novel "blended online-offline" teaching model has been constructed, implementing a level-based learning approach. The syllabus assessment points are meticulously detailed and scores are allocated step-by-step. A differentiated teaching approach is applied to certain experiments with scoring based on weight, forming a comprehensive assessment system. For the offline experiments, online control of scoring is employed, allowing students to view their grades at any time and adjust their learning status accordingly. Furthermore, an online robot Q&A platform has been established to facilitate real-time problem-solving, thereby realizing full-process teaching. This enhances the quality of Chemical Engineering Principle Experimental Course teaching, and contributes to the innovative reform of higher education in China.
In response to challenges such as homogeneity of assessment methods and low student engagement in current Chemical Engineering Principle Experimental Course teaching, this study introduces virtual simulation and “Internet +” technologies into the curriculum. A novel "blended online-offline" teaching model has been constructed, implementing a level-based learning approach. The syllabus assessment points are meticulously detailed and scores are allocated step-by-step. A differentiated teaching approach is applied to certain experiments with scoring based on weight, forming a comprehensive assessment system. For the offline experiments, online control of scoring is employed, allowing students to view their grades at any time and adjust their learning status accordingly. Furthermore, an online robot Q&A platform has been established to facilitate real-time problem-solving, thereby realizing full-process teaching. This enhances the quality of Chemical Engineering Principle Experimental Course teaching, and contributes to the innovative reform of higher education in China.
2024, 39(3): 191-198
doi: 10.3866/PKU.DXHX202309032
Abstract:
Catalysis courses are important core courses in the field of chemistry and chemical engineering. In the process of curriculum reform, integrating classroom knowledge, research progress, and practical production into teaching cases has become a practical requirement for cultivating practical innovation abilities, which is also a demand in the transformation of the new engineering disciplines. This article proposes the concept and provides some design examples of teaching cases for catalysis courses, aiming to improve the quality of catalysis course teaching and provide support for cultivating new engineering talents who can connect theory with practice and apply knowledge effectively.
Catalysis courses are important core courses in the field of chemistry and chemical engineering. In the process of curriculum reform, integrating classroom knowledge, research progress, and practical production into teaching cases has become a practical requirement for cultivating practical innovation abilities, which is also a demand in the transformation of the new engineering disciplines. This article proposes the concept and provides some design examples of teaching cases for catalysis courses, aiming to improve the quality of catalysis course teaching and provide support for cultivating new engineering talents who can connect theory with practice and apply knowledge effectively.
2024, 39(3): 199-204
doi: 10.3866/PKU.DXHX202309064
Abstract:
With continuously reforming the current educational system, the application-oriented universities have been evolving the developing mode of the integration of industry and education. Aiming to develop the students’ ability of solving problems, the infrastructure of chemistry-related courses is thus reoriented and reformatted. Classroom teaching focuses on the understanding and interpreting knowledge, while companies are aiming to reduce the production cost and improve the output for sufficient profit. The lack of communication between the two can lead students having difficulty to apply the classroom knowledge. In the teaching practice of engineering chemistry course, we combined the production of pesticide Fipronil with classroom teaching as a research topic for teaching and learning. By optimizing the chemical reaction process, we improved the production efficiency. These practices not only enrich the content of teaching topics in the classroom, but also deepen students to better understand the basic principles. Furthermore, the application of the integration practice of industrial application and classroom teaching helps students to develop their own interests in the knowledge-based problem-solving process.
With continuously reforming the current educational system, the application-oriented universities have been evolving the developing mode of the integration of industry and education. Aiming to develop the students’ ability of solving problems, the infrastructure of chemistry-related courses is thus reoriented and reformatted. Classroom teaching focuses on the understanding and interpreting knowledge, while companies are aiming to reduce the production cost and improve the output for sufficient profit. The lack of communication between the two can lead students having difficulty to apply the classroom knowledge. In the teaching practice of engineering chemistry course, we combined the production of pesticide Fipronil with classroom teaching as a research topic for teaching and learning. By optimizing the chemical reaction process, we improved the production efficiency. These practices not only enrich the content of teaching topics in the classroom, but also deepen students to better understand the basic principles. Furthermore, the application of the integration practice of industrial application and classroom teaching helps students to develop their own interests in the knowledge-based problem-solving process.
2024, 39(3): 205-209
doi: 10.3866/PKU.DXHX202309058
Abstract:
Zhejiang Agriculture and Forestry University’s Applied Chemistry program is one of the first-class program construction sites in Zhejiang Province and also one of the third batch of national-level first-class undergraduate program construction sites. This article analyzes the problems existing in the traditional talent cultivation of the program and proposes high-quality teaching resources such as co-construction of talent cultivation programs, teacher team resource pool, practical teaching base, curriculum and textbook construction, and teaching method innovation. It constructs an innovative “One body, dual wings” embedded talent cultivation model, introduces the content and guarantee measures of the model as an example, and analyzes the effectiveness of the model.
Zhejiang Agriculture and Forestry University’s Applied Chemistry program is one of the first-class program construction sites in Zhejiang Province and also one of the third batch of national-level first-class undergraduate program construction sites. This article analyzes the problems existing in the traditional talent cultivation of the program and proposes high-quality teaching resources such as co-construction of talent cultivation programs, teacher team resource pool, practical teaching base, curriculum and textbook construction, and teaching method innovation. It constructs an innovative “One body, dual wings” embedded talent cultivation model, introduces the content and guarantee measures of the model as an example, and analyzes the effectiveness of the model.
2024, 39(3): 210-217
doi: 10.3866/PKU.DXHX202309006
Abstract:
Curriculum ideological and political is the soul of Physical Chemistry education. Taking the course of Physical Chemistry of Yunnan Agricultural University as an example, this paper proposes a “seven-step teaching characteristic method” according to the educational concept of “virtue and material, unity of knowledge and action”. The teaching mode of “One central task, One critical line, Two drives, Three integrations” in physical chemistry course under the guidance of ideological and political education is interpreted from the four dimensions of teaching objectives, teaching content, theory and practice. Teaching practice shows that the teaching of physical chemistry guided by curriculum ideology and politics is very effective way to follow the needs of the times, innovated teaching content, improve students’ ability and teaching quality, cultivated students’ good moral character.
Curriculum ideological and political is the soul of Physical Chemistry education. Taking the course of Physical Chemistry of Yunnan Agricultural University as an example, this paper proposes a “seven-step teaching characteristic method” according to the educational concept of “virtue and material, unity of knowledge and action”. The teaching mode of “One central task, One critical line, Two drives, Three integrations” in physical chemistry course under the guidance of ideological and political education is interpreted from the four dimensions of teaching objectives, teaching content, theory and practice. Teaching practice shows that the teaching of physical chemistry guided by curriculum ideology and politics is very effective way to follow the needs of the times, innovated teaching content, improve students’ ability and teaching quality, cultivated students’ good moral character.
2024, 39(3): 218-230
doi: 10.3866/PKU.DXHX202308106
Abstract:
This paper summarizes the strategies of functional group addition that often appear in basic organic courses. We innovatively propose the carbonyl-oriented functional group addition of amine to synthesize different types of amines. We expect to enable students to have a more systematic and in-depth understanding of functional group addition and to build a bridge between basic course learning and practical scientific research.
This paper summarizes the strategies of functional group addition that often appear in basic organic courses. We innovatively propose the carbonyl-oriented functional group addition of amine to synthesize different types of amines. We expect to enable students to have a more systematic and in-depth understanding of functional group addition and to build a bridge between basic course learning and practical scientific research.
2024, 39(3): 231-238
doi: 10.3866/PKU.DXHX202309020
Abstract:
Amides are one of the most important classes of compounds that widely exist in bioactive molecules such as peptides and alkaloids. They also have important applications in various fields such as chemical engineering, dyes and pharmaceutical development. Therefore, studying the synthesis and structural identification of amide compounds is of great significance. Due to the delocalization of lone pair electrons from the nitrogen atom of amide compounds to the carbonyl group (C＝O), the C―N bond in the amide RCO―N exhibits partial double bond properties, preventing free rotation and resulting in complex nuclear magnetic resonance hydrogen spectrum (1H NMR). This article summarizes the characteristics of 1H NMR spectra of amides and discusses some factors influencing amide isomerization. This article will cultivate students’ ability to analyze the 1H NMR of amides and deepen their understanding and knowledge of amide compounds.
Amides are one of the most important classes of compounds that widely exist in bioactive molecules such as peptides and alkaloids. They also have important applications in various fields such as chemical engineering, dyes and pharmaceutical development. Therefore, studying the synthesis and structural identification of amide compounds is of great significance. Due to the delocalization of lone pair electrons from the nitrogen atom of amide compounds to the carbonyl group (C＝O), the C―N bond in the amide RCO―N exhibits partial double bond properties, preventing free rotation and resulting in complex nuclear magnetic resonance hydrogen spectrum (1H NMR). This article summarizes the characteristics of 1H NMR spectra of amides and discusses some factors influencing amide isomerization. This article will cultivate students’ ability to analyze the 1H NMR of amides and deepen their understanding and knowledge of amide compounds.
2024, 39(3): 239-257
doi: 10.3866/PKU.DXHX202309093
Abstract:
Cyclic organic compounds play a crucial role in organic chemistry, pharmaceutical chemistry, and materials science. Among the various methods for constructing these compounds, metal-catalyzed cycloaddition and cyclization reactions stand out as powerful approaches. In recent years, scientists have made significant advancements by developing bimetallic relay catalytic systems based on the study of single-transition-metal catalytic cyclization reactions. These bimetallic relay catalytic systems have garnered immense attention due to their ability to facilitate transformations that are unattainable through individual catalytic systems alone. This paper provides a comprehensive review of the recent progress made in the synthesis of cyclic compounds through bimetallic relay catalysis over the past five years, while also offering insights into the future directions of this exciting field.
Cyclic organic compounds play a crucial role in organic chemistry, pharmaceutical chemistry, and materials science. Among the various methods for constructing these compounds, metal-catalyzed cycloaddition and cyclization reactions stand out as powerful approaches. In recent years, scientists have made significant advancements by developing bimetallic relay catalytic systems based on the study of single-transition-metal catalytic cyclization reactions. These bimetallic relay catalytic systems have garnered immense attention due to their ability to facilitate transformations that are unattainable through individual catalytic systems alone. This paper provides a comprehensive review of the recent progress made in the synthesis of cyclic compounds through bimetallic relay catalysis over the past five years, while also offering insights into the future directions of this exciting field.
2024, 39(3): 258-265
doi: 10.3866/PKU.DXHX202309057
Abstract:
An eco-friendly modification has been implemented in the experiment of preparation and characterization of silver nanoparticles. Using tea water as both reducing agent and stabilizer, the study explored the effects of tea water concentration, pH of solution, and reaction temperature on the preparation of silver nanoparticles, thereby helping students to understand the effects of experimental conditions on the preparation of silver nanoparticles. The optical properties of silver nanoparticles were characterized by a spectrophotometer. And the relationship between absorbance and concentration of silver nanoparticle solution and Tyndall effect were demonstrated. Furthermore, the size of silver nanoparticles was determined using a laser particle size analyzer. The improved experiment is closely aligned with everyday life, rich in content, and closely following academic frontier. It also adheres to the principles of green chemistry, making it advantageous for stimulating students’ interest in learning and cultivating practical skills, critical thinking ability and innovative awareness.
An eco-friendly modification has been implemented in the experiment of preparation and characterization of silver nanoparticles. Using tea water as both reducing agent and stabilizer, the study explored the effects of tea water concentration, pH of solution, and reaction temperature on the preparation of silver nanoparticles, thereby helping students to understand the effects of experimental conditions on the preparation of silver nanoparticles. The optical properties of silver nanoparticles were characterized by a spectrophotometer. And the relationship between absorbance and concentration of silver nanoparticle solution and Tyndall effect were demonstrated. Furthermore, the size of silver nanoparticles was determined using a laser particle size analyzer. The improved experiment is closely aligned with everyday life, rich in content, and closely following academic frontier. It also adheres to the principles of green chemistry, making it advantageous for stimulating students’ interest in learning and cultivating practical skills, critical thinking ability and innovative awareness.
2024, 39(3): 266-273
doi: 10.3866/PKU.DXHX202309068
Abstract:
Instrumental analysis experiment constitutes an essential component for medical prevention and medical testing specialties. To improve the innovative and practical abilities of the undergraduates, a designed experiment of simultaneous determination of acetylsalicylic acid and caffeine in Aspirin tablets by High Performance Liquid Chromatography (HPLC) and Ultra Performance Convergence Chromatography (UPC2) was applied. Additionally, ideological and political elements were organically integrated into the teaching process. Educational practice has shown that by facilitating comparative learning of different instrument principles and functional characteristics, students’ interest in experimentation and exploratory spirit can be invigorated. This approach also strengthens students’ problem-solving skills, thereby elevating their scientific literacy.
Instrumental analysis experiment constitutes an essential component for medical prevention and medical testing specialties. To improve the innovative and practical abilities of the undergraduates, a designed experiment of simultaneous determination of acetylsalicylic acid and caffeine in Aspirin tablets by High Performance Liquid Chromatography (HPLC) and Ultra Performance Convergence Chromatography (UPC2) was applied. Additionally, ideological and political elements were organically integrated into the teaching process. Educational practice has shown that by facilitating comparative learning of different instrument principles and functional characteristics, students’ interest in experimentation and exploratory spirit can be invigorated. This approach also strengthens students’ problem-solving skills, thereby elevating their scientific literacy.
2024, 39(3): 274-282
doi: 10.3866/PKU.DXHX202309069
Abstract:
The analysis of plant essential oil components using gas chromatography-mass spectrometry (GC-MS) serves as an integral component of modern chemical experiment and technology (instrumental analysis part) for undergraduates in our college. The conventional approach of steam distillation for extracting plant essential oil suffers from limitations such as low extraction rate, solvent residue and extended processing time. Supercritical CO2 extraction, an advanced green extraction technology, offers considerable advantages for the isolation of bioactive constituents from natural plants and animals. In this experiment, citrus essential oil was extracted using supercritical CO2 extraction and compared with traditional steam distillation method. A total of 106 essential oil components were isolated using supercritical CO2 extraction, with the following distribution in terms of relative content: terpenes, aldehydes, acids, esters, ketones and alcohols, among which terpenes accounted for 89.55%. The incorporation of supercritical CO2 extraction technology into the laboratory syllabus not only enriches students’ understanding of advanced sample preparation methods but also enhances their practical skills, research acumen, and innovative thinking. Furthermore, this technology streamlines experiment timeline, reduces the use of hazardous reagents, and promotes green experiment teaching.
The analysis of plant essential oil components using gas chromatography-mass spectrometry (GC-MS) serves as an integral component of modern chemical experiment and technology (instrumental analysis part) for undergraduates in our college. The conventional approach of steam distillation for extracting plant essential oil suffers from limitations such as low extraction rate, solvent residue and extended processing time. Supercritical CO2 extraction, an advanced green extraction technology, offers considerable advantages for the isolation of bioactive constituents from natural plants and animals. In this experiment, citrus essential oil was extracted using supercritical CO2 extraction and compared with traditional steam distillation method. A total of 106 essential oil components were isolated using supercritical CO2 extraction, with the following distribution in terms of relative content: terpenes, aldehydes, acids, esters, ketones and alcohols, among which terpenes accounted for 89.55%. The incorporation of supercritical CO2 extraction technology into the laboratory syllabus not only enriches students’ understanding of advanced sample preparation methods but also enhances their practical skills, research acumen, and innovative thinking. Furthermore, this technology streamlines experiment timeline, reduces the use of hazardous reagents, and promotes green experiment teaching.
2024, 39(3): 283-293
doi: 10.3866/PKU.DXHX202308097
Abstract:
This experiment focused on the forefront and technology in chemistry, paid attention to the development of intelligent teaching, integrated computational chemistry concepts and methods into traditional experiments, and improved data analysis. Packmol was used to build models consistent with the experiment. Gromacs was used to calculate and analyze the tilt angle, rotation radius, radial distribution function, hydrogen bond and solvent-accessible surface area to study the adsorption characteristics from the microscopic level. This comprehensive experiment could enable students to understand the microstructure changes in the adsorption and emulsification process of surfactants from the atomic scale, stimulate students’ interest in learning, improve their software application and spatial imagination ability, and enrich the course design of physical chemistry experiments related to interface chemistry experiments.
This experiment focused on the forefront and technology in chemistry, paid attention to the development of intelligent teaching, integrated computational chemistry concepts and methods into traditional experiments, and improved data analysis. Packmol was used to build models consistent with the experiment. Gromacs was used to calculate and analyze the tilt angle, rotation radius, radial distribution function, hydrogen bond and solvent-accessible surface area to study the adsorption characteristics from the microscopic level. This comprehensive experiment could enable students to understand the microstructure changes in the adsorption and emulsification process of surfactants from the atomic scale, stimulate students’ interest in learning, improve their software application and spatial imagination ability, and enrich the course design of physical chemistry experiments related to interface chemistry experiments.
2024, 39(3): 294-301
doi: 10.3866/PKU.DXHX202308103
Abstract:
The expansion and extension of the liquid saturated vapor pressure measurement experiment involves determining the saturated vapor pressure of a liquid within a certain temperature range and using the Clausius-Clapeyron equation to obtain the molar evaporation enthalpy. Since the molar evaporation enthalpy is a function of temperature, its values differ in different temperature ranges, resulting in relatively large relative errors. The method of selecting temperature ranges based on the calculation of molar evaporation enthalpy to reduce experimental errors has not been applied in experimental teaching. In this experiment, pure water is chosen as the research object instead of organic reagents, and the average molar evaporation enthalpy of water in different temperature ranges is calculated using the method of Kirchhoff’s law, which serves as a reference to determine the optimal temperature measurement range. Furthermore, the determination of the saturated vapor pressure of pure liquid is expanded to electrolyte and non-electrolyte solutions using Raoult’s law, which can be linked to more theoretical teaching content. The experimental results show that the error in measuring the saturated vapor pressure of pure water within the range of 40–60 °C is small, and the molar evaporation enthalpy obtained using the experimental results is in good agreement with the calculated value, with an error of only 0.465%. Expanding this method to the determination of the saturated vapor pressure of sucrose and NaCl solutions can further verify the necessity of introducing activity coefficients in Raoult’s law and the importance of studying non-ideal dilute solutions. In addition, using virtual simulation technology to demonstrate the flow of gas molecules and the change in system pressure in the static method can enhance visualization and make the experimental principle clear and easy to understand.
The expansion and extension of the liquid saturated vapor pressure measurement experiment involves determining the saturated vapor pressure of a liquid within a certain temperature range and using the Clausius-Clapeyron equation to obtain the molar evaporation enthalpy. Since the molar evaporation enthalpy is a function of temperature, its values differ in different temperature ranges, resulting in relatively large relative errors. The method of selecting temperature ranges based on the calculation of molar evaporation enthalpy to reduce experimental errors has not been applied in experimental teaching. In this experiment, pure water is chosen as the research object instead of organic reagents, and the average molar evaporation enthalpy of water in different temperature ranges is calculated using the method of Kirchhoff’s law, which serves as a reference to determine the optimal temperature measurement range. Furthermore, the determination of the saturated vapor pressure of pure liquid is expanded to electrolyte and non-electrolyte solutions using Raoult’s law, which can be linked to more theoretical teaching content. The experimental results show that the error in measuring the saturated vapor pressure of pure water within the range of 40–60 °C is small, and the molar evaporation enthalpy obtained using the experimental results is in good agreement with the calculated value, with an error of only 0.465%. Expanding this method to the determination of the saturated vapor pressure of sucrose and NaCl solutions can further verify the necessity of introducing activity coefficients in Raoult’s law and the importance of studying non-ideal dilute solutions. In addition, using virtual simulation technology to demonstrate the flow of gas molecules and the change in system pressure in the static method can enhance visualization and make the experimental principle clear and easy to understand.
2024, 39(3): 302-307
doi: 10.3866/PKU.DXHX202308095
Abstract:
Based on the “Electrolysis-Gasometric Determination of Avogadro’s Constant” experiment offered to freshmen, an integrated experiment was designed for the electrochemical synthesis of Cu2O and determination of Avogadro’s constant by aerometry. This experiment ingeniously integrates the preparation and property study of Cu2O from elemental chemistry experiments. A single electrolytic process accomplishes two experiments, save both electricity and time. The integrated experiment can be flexibly interspersed within the foundational chemistry experiment curriculum in universities. It holds great significance for cultivating students’ holistic thinking, multi-faced problem-solving abilities, as well as the concepts of economic and environmental conservation.
Based on the “Electrolysis-Gasometric Determination of Avogadro’s Constant” experiment offered to freshmen, an integrated experiment was designed for the electrochemical synthesis of Cu2O and determination of Avogadro’s constant by aerometry. This experiment ingeniously integrates the preparation and property study of Cu2O from elemental chemistry experiments. A single electrolytic process accomplishes two experiments, save both electricity and time. The integrated experiment can be flexibly interspersed within the foundational chemistry experiment curriculum in universities. It holds great significance for cultivating students’ holistic thinking, multi-faced problem-solving abilities, as well as the concepts of economic and environmental conservation.
2024, 39(3): 308-315
doi: 10.3866/PKU.DXHX202309003
Abstract:
This experiment designs a PET (polyethylene terephthalate) plastic electrocatalysis upgrading and regeneration strategy driven by renewable energy, converting discarded PET plastic into high-value-added chemicals such as terephthalic acid and potassium formate, while simultaneously co-producing hydrogen (H2). The specific experimental process includes firstly degrading PET plastic into terephthalic acid and ethylene glycol monomer through hydrothermal method, then selectively electrocatalyzing the oxidation of ethylene glycol to formate using a self-made hydrotalcite catalyst (layered double hydroxide, LDH) while co-producing H2 at the cathode, and finally obtaining potassium formate and terephthalic acid products through separation and purification steps such as acidification, vacuum filtration, rotary evaporation, and vacuum drying. This experiment is a typical case of introducing research results into teaching, providing new ideas for the green upgrading and regeneration of discarded PET plastic resources, and promoting students’ scientific thinking ability and interest in scientific research.
This experiment designs a PET (polyethylene terephthalate) plastic electrocatalysis upgrading and regeneration strategy driven by renewable energy, converting discarded PET plastic into high-value-added chemicals such as terephthalic acid and potassium formate, while simultaneously co-producing hydrogen (H2). The specific experimental process includes firstly degrading PET plastic into terephthalic acid and ethylene glycol monomer through hydrothermal method, then selectively electrocatalyzing the oxidation of ethylene glycol to formate using a self-made hydrotalcite catalyst (layered double hydroxide, LDH) while co-producing H2 at the cathode, and finally obtaining potassium formate and terephthalic acid products through separation and purification steps such as acidification, vacuum filtration, rotary evaporation, and vacuum drying. This experiment is a typical case of introducing research results into teaching, providing new ideas for the green upgrading and regeneration of discarded PET plastic resources, and promoting students’ scientific thinking ability and interest in scientific research.
2024, 39(3): 316-326
doi: 10.3866/PKU.DXHX202309091
Abstract:
In the teaching process of the organic chemistry experiment, the content typically involves the synthesis or extraction of a certain compound, often lacking in structural identification and property testing of the target compound. To improve the quality of organic chemistry experimental teaching, and cultivate students’ scientific research literacy and innovation ability, commercially available aldehydes, ketones and p-toluenesulfonyl hydrazide are used as reactants. N-tosylhydrazone derivatives were effectively synthesized within 1 min under solvent-free conditions by using a grinding method at room temperature, and the structure and properties of the products were also studied. Compounds 3i and 3h have the best inhibitory effect against Escherichia coli during antibacterial experimental research. The experiment, encompassing synthesis, TLC detection, and column chromatography operations, serves to hone students’ operational skills in organic compound synthesis, purification, and structural identification. Students are required to consult literature independently and proficiently utilize software tools like Origin, ChemDraw and MestRec, which fosters their ability to analyze and resolve problems. This improved experimental framework, aimed at elevating students’ comprehensive qualities, is well-suited for the foundational organic chemistry experimental teaching.
In the teaching process of the organic chemistry experiment, the content typically involves the synthesis or extraction of a certain compound, often lacking in structural identification and property testing of the target compound. To improve the quality of organic chemistry experimental teaching, and cultivate students’ scientific research literacy and innovation ability, commercially available aldehydes, ketones and p-toluenesulfonyl hydrazide are used as reactants. N-tosylhydrazone derivatives were effectively synthesized within 1 min under solvent-free conditions by using a grinding method at room temperature, and the structure and properties of the products were also studied. Compounds 3i and 3h have the best inhibitory effect against Escherichia coli during antibacterial experimental research. The experiment, encompassing synthesis, TLC detection, and column chromatography operations, serves to hone students’ operational skills in organic compound synthesis, purification, and structural identification. Students are required to consult literature independently and proficiently utilize software tools like Origin, ChemDraw and MestRec, which fosters their ability to analyze and resolve problems. This improved experimental framework, aimed at elevating students’ comprehensive qualities, is well-suited for the foundational organic chemistry experimental teaching.
2024, 39(3): 327-335
doi: 10.3866/PKU.DXHX202309074
Abstract:
This article presents a comprehensive computational chemistry experiment designed for senior undergraduate students majoring in chemistry. The experiment utilizes quantum chemical calculations to study a typical Diels-Alder reaction found in organic chemistry textbooks. It provides a microscopic physical picture of the reaction process, as well as quantitative information on the thermodynamic and kinetic properties of the reaction, elucidating the fundamental concepts of thermodynamic control and kinetic control in chemical reactions. The objective of this experiment is to cultivate students’ basic skills in using computational chemistry methods to investigate chemical problems and deepen their understanding of the relationship between molecular structure and properties. Additionally, the experiment serves as a specific example of dialectical materialism worldview and methodology education for students, emphasizing the importance of recognizing the universality of contradictions and developing the ability to analyze and solve practical chemical problems using a holistic and developmental perspective.
This article presents a comprehensive computational chemistry experiment designed for senior undergraduate students majoring in chemistry. The experiment utilizes quantum chemical calculations to study a typical Diels-Alder reaction found in organic chemistry textbooks. It provides a microscopic physical picture of the reaction process, as well as quantitative information on the thermodynamic and kinetic properties of the reaction, elucidating the fundamental concepts of thermodynamic control and kinetic control in chemical reactions. The objective of this experiment is to cultivate students’ basic skills in using computational chemistry methods to investigate chemical problems and deepen their understanding of the relationship between molecular structure and properties. Additionally, the experiment serves as a specific example of dialectical materialism worldview and methodology education for students, emphasizing the importance of recognizing the universality of contradictions and developing the ability to analyze and solve practical chemical problems using a holistic and developmental perspective.
2024, 39(3): 336-344
doi: 10.3866/PKU.DXHX202309002
Abstract:
Polyaniline, as one of the most widely studied conductive polymer materials, has been widely used in many fields. The chemical synthesis experiment of polyaniline is a representative experiment in the teaching of materials chemistry and related subjects. However, this experiment has several shortcomings, such as the high sensitivity of product properties to solvent selection, dopant types, reaction time, temperature, limited characterization methods, unstable yield, and poor reproducibility. This experiment is an improvement of the “Chemical Synthesis of Polyaniline” experiment, where the original chemical synthesis method is replaced with an electrochemical synthesis method. It combines instrumental analysis experiments such as “Cyclic Voltammetry Analysis” and open-ended experiments such as “Preparation of Anticorrosive Coatings” to transform it from a confirmatory preparation experiment to an innovative design experiment that integrates autonomous selection of preparation conditions and testing of anticorrosive properties. This allows students to learn the synthesis, doping, and related electrochemical knowledge of polyaniline in a coherent manner, leading to a clearer understanding of the wide-ranging applications of conductive polymers. This improved experiment is rich in content and better aligns with the development of modern chemistry and materials science, helping students integrate theoretical knowledge from multiple courses and enhance their comprehensive skills.
Polyaniline, as one of the most widely studied conductive polymer materials, has been widely used in many fields. The chemical synthesis experiment of polyaniline is a representative experiment in the teaching of materials chemistry and related subjects. However, this experiment has several shortcomings, such as the high sensitivity of product properties to solvent selection, dopant types, reaction time, temperature, limited characterization methods, unstable yield, and poor reproducibility. This experiment is an improvement of the “Chemical Synthesis of Polyaniline” experiment, where the original chemical synthesis method is replaced with an electrochemical synthesis method. It combines instrumental analysis experiments such as “Cyclic Voltammetry Analysis” and open-ended experiments such as “Preparation of Anticorrosive Coatings” to transform it from a confirmatory preparation experiment to an innovative design experiment that integrates autonomous selection of preparation conditions and testing of anticorrosive properties. This allows students to learn the synthesis, doping, and related electrochemical knowledge of polyaniline in a coherent manner, leading to a clearer understanding of the wide-ranging applications of conductive polymers. This improved experiment is rich in content and better aligns with the development of modern chemistry and materials science, helping students integrate theoretical knowledge from multiple courses and enhance their comprehensive skills.
2024, 39(3): 345-350
doi: 10.3866/PKU.DXHX202309010
Abstract:
Organic chemistry experiments involve complex procedures and the use of various instruments and reagents. Traditional laboratory safety education has been lacking in the identification of potential hazards in experiments. Taking the synthesis of triphenylmethanol as an example, we break down the experimental procedures into multiple steps, guiding students to identify the hazards involved in each step of the operation. We share relevant typical cases with students and reinforce their awareness of experiment safety through accident examples. By repeatedly practicing hazard identification in different experimental projects, students become proficient in the safe operation of common hazards in chemical synthesis experiments and are able to proactively analyze hazards, take personal protective measures, and strictly follow safety protocols in new experiments
Organic chemistry experiments involve complex procedures and the use of various instruments and reagents. Traditional laboratory safety education has been lacking in the identification of potential hazards in experiments. Taking the synthesis of triphenylmethanol as an example, we break down the experimental procedures into multiple steps, guiding students to identify the hazards involved in each step of the operation. We share relevant typical cases with students and reinforce their awareness of experiment safety through accident examples. By repeatedly practicing hazard identification in different experimental projects, students become proficient in the safe operation of common hazards in chemical synthesis experiments and are able to proactively analyze hazards, take personal protective measures, and strictly follow safety protocols in new experiments
2024, 39(3): 351-358
doi: 10.3866/PKU.DXHX202309060
Abstract:
The status of machine learning in chemistry and related disciplines is becoming increasingly prominent, but its application in undergraduate chemistry experiments has yet to be seen. Existing computational chemistry experiments mostly focus on the application of quantum chemistry methods to study molecular properties and chemical reactions. In order to popularize machine learning as a powerful tool, this article will introduce a comprehensive computational chemistry experiment suitable for senior undergraduate students or graduate students. Through this experiment, students can gain a preliminary understanding of the basic principles and operational procedures of machine learning, while also develop their ability to apply quantum chemistry and machine learning to solve chemical problems.
The status of machine learning in chemistry and related disciplines is becoming increasingly prominent, but its application in undergraduate chemistry experiments has yet to be seen. Existing computational chemistry experiments mostly focus on the application of quantum chemistry methods to study molecular properties and chemical reactions. In order to popularize machine learning as a powerful tool, this article will introduce a comprehensive computational chemistry experiment suitable for senior undergraduate students or graduate students. Through this experiment, students can gain a preliminary understanding of the basic principles and operational procedures of machine learning, while also develop their ability to apply quantum chemistry and machine learning to solve chemical problems.
2024, 39(3): 359-368
doi: 10.3866/PKU.DXHX202308094
Abstract:
With the strategic implementation of carbon peaking and carbon neutrality, the demand for advanced energy storage technology is rapidly increasing. Among these, the electrochemical energy storage technologies have been evolving rapidly, and have attracted intensive attention from academia and industrial sectors. In comparison with lithium-ion batteries, magnesium batteries have emerged as an important direction for developing next-generation rechargeable batteries, in view of their higher energy densities, lower cost, higher natural abundance, and environmental friendliness. For classic non-aqueous electrolytes, the formation of the passivation films with low ionic conductivities on magnesium anodes significantly hinders the electrochemical dissolution/deposition of magnesium ions, thereby greatly limiting the development of magnesium batteries. Therefore, the exploration of high-performing magnesium-ion conductive electrolyte systems is a key direction in improving the performance of magnesium batteries. In this work, from the perspective of the classical organic chemistry experiment of “Grignard reaction”, we concentrate on the preparation of magnesium-ion conductive non-aqueous electrolytes and their application in magnesium battery systems. We combine the fundamentals of organic chemistry with cutting-edge technology in electrochemical energy storage, thus helping students to expand their scientific horizons, stimulating their research interests and improving their awareness of energy security and scientific literacy.
With the strategic implementation of carbon peaking and carbon neutrality, the demand for advanced energy storage technology is rapidly increasing. Among these, the electrochemical energy storage technologies have been evolving rapidly, and have attracted intensive attention from academia and industrial sectors. In comparison with lithium-ion batteries, magnesium batteries have emerged as an important direction for developing next-generation rechargeable batteries, in view of their higher energy densities, lower cost, higher natural abundance, and environmental friendliness. For classic non-aqueous electrolytes, the formation of the passivation films with low ionic conductivities on magnesium anodes significantly hinders the electrochemical dissolution/deposition of magnesium ions, thereby greatly limiting the development of magnesium batteries. Therefore, the exploration of high-performing magnesium-ion conductive electrolyte systems is a key direction in improving the performance of magnesium batteries. In this work, from the perspective of the classical organic chemistry experiment of “Grignard reaction”, we concentrate on the preparation of magnesium-ion conductive non-aqueous electrolytes and their application in magnesium battery systems. We combine the fundamentals of organic chemistry with cutting-edge technology in electrochemical energy storage, thus helping students to expand their scientific horizons, stimulating their research interests and improving their awareness of energy security and scientific literacy.
2024, 39(3): 369-375
doi: 10.3866/PKU.DXHX202309047
Abstract:
Chemistry comprehensive experiment is in the basic core position in university chemistry teaching. Combined with the our latest research results, we designed a visible light-induced synthesis of selenium-containing seven-membered medium-sized N-heterocycles comprehensive experiment. Through substrate design and preparation→visible light catalysis synthesis→structure characterisation and analysis, students are systematically trained in skills such as continuous multi-step synthetic operation, process analysis and structure analysis, so as to cultivate the systematic and comprehensive nature of students’ learning. On this basis, students can fully understand the frontiers and advantages of photochemical reactions and cultivate their awareness of green chemistry.
Chemistry comprehensive experiment is in the basic core position in university chemistry teaching. Combined with the our latest research results, we designed a visible light-induced synthesis of selenium-containing seven-membered medium-sized N-heterocycles comprehensive experiment. Through substrate design and preparation→visible light catalysis synthesis→structure characterisation and analysis, students are systematically trained in skills such as continuous multi-step synthetic operation, process analysis and structure analysis, so as to cultivate the systematic and comprehensive nature of students’ learning. On this basis, students can fully understand the frontiers and advantages of photochemical reactions and cultivate their awareness of green chemistry.
2024, 39(3): 376-383
doi: 10.3866/PKU.DXHX202305027
Abstract:
Atomic structure, a fundamental topic and teaching difficulty in inorganic chemistry, poses significant challenges for educators. Overcoming these obstacles has remained a constant concern for teachers, necessitating urgent solutions. In this study, we explore the teaching process of atomic structure by employing a meticulously crafted classroom approach, centered around the principles of quantum mechanics, and interweaving the entire curriculum. Emphasizing the importance of active student engagement, we encourage thorough preparation, leverage problem-oriented teaching methods, and harness the power of multimedia tools to transform dry and monotonous content into vivid and captivating lessons. By instilling an appreciation for the historical context and development of atomic structure, we aim to nurture students’ scientific spirit and foster their innovative abilities. Ultimately, our approach strives to enhance students’ learning, comprehension, and mastery of the subject matter, resulting in improved classroom teaching quality and heightened learning efficiency of students.
Atomic structure, a fundamental topic and teaching difficulty in inorganic chemistry, poses significant challenges for educators. Overcoming these obstacles has remained a constant concern for teachers, necessitating urgent solutions. In this study, we explore the teaching process of atomic structure by employing a meticulously crafted classroom approach, centered around the principles of quantum mechanics, and interweaving the entire curriculum. Emphasizing the importance of active student engagement, we encourage thorough preparation, leverage problem-oriented teaching methods, and harness the power of multimedia tools to transform dry and monotonous content into vivid and captivating lessons. By instilling an appreciation for the historical context and development of atomic structure, we aim to nurture students’ scientific spirit and foster their innovative abilities. Ultimately, our approach strives to enhance students’ learning, comprehension, and mastery of the subject matter, resulting in improved classroom teaching quality and heightened learning efficiency of students.
2024, 39(3): 384-389
doi: 10.3866/PKU.DXHX202309065
Abstract:
The copper(II)-ammonia coordination ion represents a quintessential model for understanding the coordination equilibrium and distribution characteristics of coordination compounds in the teaching of analytical chemistry. Current textbooks, however, often limit their scope to providing stability constants for select copper-ammonia coordination ions, without delving into the correlation between their coordination numbers and stability. This study leverages density functional theory to firstly establish a connection between the stability of copper-ammonia coordination ions and their coordination numbers, achieved through structural optimization. Subsequently, it offers a qualitative interpretation by examining the molecule spatial configuration, shedding light on the fundamental nature of these structures. This research not only enhances the effectiveness of pedagogical approaches, but also cultivates students' interest in the application of the theoretical calculations within the realm of analytical chemistry.
The copper(II)-ammonia coordination ion represents a quintessential model for understanding the coordination equilibrium and distribution characteristics of coordination compounds in the teaching of analytical chemistry. Current textbooks, however, often limit their scope to providing stability constants for select copper-ammonia coordination ions, without delving into the correlation between their coordination numbers and stability. This study leverages density functional theory to firstly establish a connection between the stability of copper-ammonia coordination ions and their coordination numbers, achieved through structural optimization. Subsequently, it offers a qualitative interpretation by examining the molecule spatial configuration, shedding light on the fundamental nature of these structures. This research not only enhances the effectiveness of pedagogical approaches, but also cultivates students' interest in the application of the theoretical calculations within the realm of analytical chemistry.
2024, 39(3): 390-394
doi: 10.3866/PKU.DXHX202309030
Abstract:
Buffer capacity is an important concept in analytical chemistry. Conventional calculations often neglect volume changes that occurs when a buffer solution mixes with a sample solution, yielding what is termed “static” buffer capacity. In practical applications, however, the volume of the buffer solution mixed with the sample solution is often substantially greater than the original volume of the buffer solution, therefore necessitating the consideration of “dynamic” buffer capacity in textbook. This paper proposes a “de-formulized” strategy for addressing “dynamic” buffer capacity problem, which is completely based on the underlying logic of the discipline. This approach avoids adding to the memorization burden of students’ learning.
Buffer capacity is an important concept in analytical chemistry. Conventional calculations often neglect volume changes that occurs when a buffer solution mixes with a sample solution, yielding what is termed “static” buffer capacity. In practical applications, however, the volume of the buffer solution mixed with the sample solution is often substantially greater than the original volume of the buffer solution, therefore necessitating the consideration of “dynamic” buffer capacity in textbook. This paper proposes a “de-formulized” strategy for addressing “dynamic” buffer capacity problem, which is completely based on the underlying logic of the discipline. This approach avoids adding to the memorization burden of students’ learning.
2024, 39(3): 395-400
doi: 10.3866/PKU.DXHX202309018
Abstract:
Chemistry is no longer a pure experimental science. Theoretical calculations and chemical experiments can be used to study the properties of compounds and chemical reactions from different perspectives. Now, calculation is an important branch of chemical research. In this manuscript, through a specific calculation study on the mechanism of CO2 functionalization reduction reaction of aniline, the basic methods and processes of quantum calculation are introduced and some reaction details that are easily overlooked or cannot be discovered during the experimental process are discovered by analyzing the calculation results.
Chemistry is no longer a pure experimental science. Theoretical calculations and chemical experiments can be used to study the properties of compounds and chemical reactions from different perspectives. Now, calculation is an important branch of chemical research. In this manuscript, through a specific calculation study on the mechanism of CO2 functionalization reduction reaction of aniline, the basic methods and processes of quantum calculation are introduced and some reaction details that are easily overlooked or cannot be discovered during the experimental process are discovered by analyzing the calculation results.
