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2020 Volume 39 Issue 6
2020, 39(6): 989-998
doi: 10.14102/j.cnki.0254-5861.2011-2886
Abstract:
Metal clusters that contain a small number of atoms usually present unique properties with dramatic dependence on their sizes, geometric structures, and compositions. The studies of naked metal clusters are devoted to develop new catalysts and functional materials of atomic precision, and enable to improve the fundamental theory of structure chemistry and to understand the basic reactions and properties bridging the gap between atoms and bulk materials. In particular, some interesting superatom clusters have received reasonable research interest indicative of materials gene of clusters. Here in this review, we simply summarize the preparation, stability, and reactivity of naked metal clusters with a few examples displayed. Hopefully it serves as a modest spur to stimulate more interest of related investigations in this field.
Metal clusters that contain a small number of atoms usually present unique properties with dramatic dependence on their sizes, geometric structures, and compositions. The studies of naked metal clusters are devoted to develop new catalysts and functional materials of atomic precision, and enable to improve the fundamental theory of structure chemistry and to understand the basic reactions and properties bridging the gap between atoms and bulk materials. In particular, some interesting superatom clusters have received reasonable research interest indicative of materials gene of clusters. Here in this review, we simply summarize the preparation, stability, and reactivity of naked metal clusters with a few examples displayed. Hopefully it serves as a modest spur to stimulate more interest of related investigations in this field.
2020, 39(6): 999-1008
doi: 10.14102/j.cnki.0254-5861.2011-2889
Abstract:
Persistent homology is a powerful and novel tool for quantifying the inherent topological features of structure. In this work, we used the persistent homology for the first time to study the closo-carboranes C2Bn-2Hn (n = 5~20) and their parent structures closo-boranes dianions BnHn2- (n = 5~20), where multiple elements are present. All these structures are first investigated with the standard Vitoris-Rips complex. We interpret all barcodes representation and associate them with structural details. By means of average bar length, a linear regression model was established to construct the relationship between persistent homology features and molecular stability, which was expressed by the relative energies. For closo-boranes dianions, we only use B atom set since B and H atoms are in pairs. The average lengths of β0, β1 and β2 bars are used as the features for linear regression, and excellent correlation coefficient (0.977) between the values predicted by persistent homology and those by quantum calculations was achieved. For closo-carboranes, C–B atom set (ignore the differences in the atoms), B atom set and C atom set were considered to get the persistent homology features (since there were only two C atoms in C2Bn-2Hn, only β0 bars were considered), and seven average bar lengths were calculated, respectively. Pearson coefficient of 0.937 was obtained. We found that the stability of carboranes showed a high linear correlation with the characteristics generated from topological bars in H0, H1 and H2. The results show that the topological information generated by persistent homology can be extended and applied to multi-element systems.
Persistent homology is a powerful and novel tool for quantifying the inherent topological features of structure. In this work, we used the persistent homology for the first time to study the closo-carboranes C2Bn-2Hn (n = 5~20) and their parent structures closo-boranes dianions BnHn2- (n = 5~20), where multiple elements are present. All these structures are first investigated with the standard Vitoris-Rips complex. We interpret all barcodes representation and associate them with structural details. By means of average bar length, a linear regression model was established to construct the relationship between persistent homology features and molecular stability, which was expressed by the relative energies. For closo-boranes dianions, we only use B atom set since B and H atoms are in pairs. The average lengths of β0, β1 and β2 bars are used as the features for linear regression, and excellent correlation coefficient (0.977) between the values predicted by persistent homology and those by quantum calculations was achieved. For closo-carboranes, C–B atom set (ignore the differences in the atoms), B atom set and C atom set were considered to get the persistent homology features (since there were only two C atoms in C2Bn-2Hn, only β0 bars were considered), and seven average bar lengths were calculated, respectively. Pearson coefficient of 0.937 was obtained. We found that the stability of carboranes showed a high linear correlation with the characteristics generated from topological bars in H0, H1 and H2. The results show that the topological information generated by persistent homology can be extended and applied to multi-element systems.
2020, 39(6): 1009-1018
doi: 10.14102/j.cnki.0254-5861.2011-2891
Abstract:
While rare-earth borides represent a class of important materials in modern industries, there are few fundamental researches on their electronic structures and physicochemical properties. Recently, we have performed combined experimental and theoretical studies on rare-earth boron clusters and their cluster-assembled complexes, revealing a series of rare-earth inverse sandwich clusters with fascinating electronic structures and chemical bonding patterns. In this overview article, we summarize recent progresses in this area and provide a perspective view on the future development of rare-earth boride clusters. Understanding the electronic structures of these clusters helps to design materials of f-element (lanthanide and actinide) borides with critical physiochemical properties.
While rare-earth borides represent a class of important materials in modern industries, there are few fundamental researches on their electronic structures and physicochemical properties. Recently, we have performed combined experimental and theoretical studies on rare-earth boron clusters and their cluster-assembled complexes, revealing a series of rare-earth inverse sandwich clusters with fascinating electronic structures and chemical bonding patterns. In this overview article, we summarize recent progresses in this area and provide a perspective view on the future development of rare-earth boride clusters. Understanding the electronic structures of these clusters helps to design materials of f-element (lanthanide and actinide) borides with critical physiochemical properties.
2020, 39(6): 1019-1028
doi: 10.14102/j.cnki.0254-5861.2011-2553
Abstract:
In this work, well-defined 1D/1D WO3 nanorod/TiO2 nanobelt (WNR/TNB) hybrid heterostructure was fabricated by a simple electrostatic self-assembly method. The structure-property correlation was clarified by characterizing the crystal phases, morphologies, optical properties, photoluminescence and photocatalytic performances of the WNR/TNB heterostructures. It was demonstrated that photocatalytic performances of WNR/TNB heterostructure toward mineralization was superior to blank TNB, WNR and randomly mixed counterparts under simulated solar light irradiation, owing predominantly to the intimate interfacial contact between WNR and TNB, forming intimately integrated heterojunction, which promotes the spatial charge carriers transfer and electron relay, hence prolonging the lifetime of photogenerated electron-hole pairs. Moreover, photocatalytic mechanism was elucidated. It is anticipated that our work would provide an alternative strategy to construct diverse heterostructured photocatalysts for solar energy conversion.
In this work, well-defined 1D/1D WO3 nanorod/TiO2 nanobelt (WNR/TNB) hybrid heterostructure was fabricated by a simple electrostatic self-assembly method. The structure-property correlation was clarified by characterizing the crystal phases, morphologies, optical properties, photoluminescence and photocatalytic performances of the WNR/TNB heterostructures. It was demonstrated that photocatalytic performances of WNR/TNB heterostructure toward mineralization was superior to blank TNB, WNR and randomly mixed counterparts under simulated solar light irradiation, owing predominantly to the intimate interfacial contact between WNR and TNB, forming intimately integrated heterojunction, which promotes the spatial charge carriers transfer and electron relay, hence prolonging the lifetime of photogenerated electron-hole pairs. Moreover, photocatalytic mechanism was elucidated. It is anticipated that our work would provide an alternative strategy to construct diverse heterostructured photocatalysts for solar energy conversion.
2020, 39(6): 1029-1034
doi: 10.14102/j.cnki.0254-5861.2011-2576
Abstract:
Al-BTC MOFs were prepared in a facile manner via a solvothermal reaction and characterized using FT-IR, XRD, and SEM. The compound was then evaluated as an adsorbent to remove Congo red (CR) from an aqueous solution. The adsorption kinetics was evaluated using the pseudo-first-order and pseudo-second-order, and it was found that the adsorption of CR onto the MOFs was well described by the pseudo-second-order equation. The as-prepared MOFs adsorbent seems to be a promising material in practice for dyes removal from aqueous solution.
Al-BTC MOFs were prepared in a facile manner via a solvothermal reaction and characterized using FT-IR, XRD, and SEM. The compound was then evaluated as an adsorbent to remove Congo red (CR) from an aqueous solution. The adsorption kinetics was evaluated using the pseudo-first-order and pseudo-second-order, and it was found that the adsorption of CR onto the MOFs was well described by the pseudo-second-order equation. The as-prepared MOFs adsorbent seems to be a promising material in practice for dyes removal from aqueous solution.
2020, 39(6): 1035-1043
doi: 10.14102/j.cnki.0254-5861.2011-2529
Abstract:
In this paper, we present a novel, reliable and sensitive electrochemical sensor for the determination of paracetamol based on hollow carbon Co3O4 nanosheets/reduced graphene oxide composite (Co3O4/r-GO). The Co3O4/r-GO was prepared via a rapid one-step microwave solvothermal process. Some series of techniques that included scanning electron microscopy, X-ray diffraction and Raman were carried out to characterize the morphology and structure of as-prepared materials. Most importantly, the developed electrochemical sensor exhibited a wide linear range of 0.05 to 900.0 μM and a low detection limit of 14.0 nM (S/N = 3) by using differential pulse voltammetry. Furthermore, the selectivity, repeatability, stability and practical applicability were further studied with satisfactory results.
In this paper, we present a novel, reliable and sensitive electrochemical sensor for the determination of paracetamol based on hollow carbon Co3O4 nanosheets/reduced graphene oxide composite (Co3O4/r-GO). The Co3O4/r-GO was prepared via a rapid one-step microwave solvothermal process. Some series of techniques that included scanning electron microscopy, X-ray diffraction and Raman were carried out to characterize the morphology and structure of as-prepared materials. Most importantly, the developed electrochemical sensor exhibited a wide linear range of 0.05 to 900.0 μM and a low detection limit of 14.0 nM (S/N = 3) by using differential pulse voltammetry. Furthermore, the selectivity, repeatability, stability and practical applicability were further studied with satisfactory results.
2020, 39(6): 1044-1050
doi: 10.14102/j.cnki.0254-5861.2011-2550
Abstract:
Enantiomerically pure lanthanide(Ⅲ)-based phosphonates are successfully synthesized by using (R)- or (S)-(1-phenylethylamino)-methylphosphonate acid (pempH2), namely, R- or S-[Tb3(pempH2)2(pempH)7]- Cl2·H2O (R-Tb or S-Tb), crystallizing in chiral space group P212121. Compound R-Tb shows a one-dimensional homochiral triple-stranded helical chain structure where the Tb(Ⅲ) atoms are bridged by O-P-O units and μ3-O(P) bridge. The thermal analysis, photoluminescence as well as optically active properties of compounds R-Tb and S-Tb have also been investigated.
Enantiomerically pure lanthanide(Ⅲ)-based phosphonates are successfully synthesized by using (R)- or (S)-(1-phenylethylamino)-methylphosphonate acid (pempH2), namely, R- or S-[Tb3(pempH2)2(pempH)7]- Cl2·H2O (R-Tb or S-Tb), crystallizing in chiral space group P212121. Compound R-Tb shows a one-dimensional homochiral triple-stranded helical chain structure where the Tb(Ⅲ) atoms are bridged by O-P-O units and μ3-O(P) bridge. The thermal analysis, photoluminescence as well as optically active properties of compounds R-Tb and S-Tb have also been investigated.
2020, 39(6): 1051-1056
doi: 10.14102/j.cnki.0254-5861.2011-2547
Abstract:
Two N-donor auxiliary ligands mediated Zn(Ⅱ) coordination polymers, namely, {[Zn(Hnbta)-(bimm)](3H2O)}n (1) and {[Zn1.5(nbta)(pyim)(H2O)](2H2O)}n (2) (H3nbta = 5-nitro-1, 2, 3-benzenetricarboxylic acid, bimm = bis(imidazol-1-yl)methane and pyim = N-(4-pyridylmethyl)imidazole), have been prepared by the hydrothermal reaction. Their structures were determined by single-crystal X-ray diffraction analysis, elemental analyses and infrared spectra. Compound 1 possesses a one-dimensional (1D) chain structure, while compound 2 features a two-dimensional (2D) network. In addition, they both exhibit high thermal stabilities and photoluminescent properties in the solid, and can be explored as potential luminescent materials.
Two N-donor auxiliary ligands mediated Zn(Ⅱ) coordination polymers, namely, {[Zn(Hnbta)-(bimm)](3H2O)}n (1) and {[Zn1.5(nbta)(pyim)(H2O)](2H2O)}n (2) (H3nbta = 5-nitro-1, 2, 3-benzenetricarboxylic acid, bimm = bis(imidazol-1-yl)methane and pyim = N-(4-pyridylmethyl)imidazole), have been prepared by the hydrothermal reaction. Their structures were determined by single-crystal X-ray diffraction analysis, elemental analyses and infrared spectra. Compound 1 possesses a one-dimensional (1D) chain structure, while compound 2 features a two-dimensional (2D) network. In addition, they both exhibit high thermal stabilities and photoluminescent properties in the solid, and can be explored as potential luminescent materials.
2020, 39(6): 1057-1062
doi: 10.14102/j.cnki.0254-5861.2011-2549
Abstract:
The syntheses, crystal structures and catalytic activities of two copper complexes are reported. Reaction of CuCl, 3-(pyridin-2-yl)imidazo[1, 5-a]pyridine and pyridine-4-formaldehyde under solvothermal conditions gave [Cu4(L1)2Cl2][CuCl2]2 (1, L1 = 1, 1΄-(pyridin-4-ylmethylene)bis(3-(pyridin-2-yl)imidazo[1, 5-a]pyridine). The ligand L1 was generated in situ from the reaction of 3-(pyridin-2-yl)imidazo[1, 5-a]pyridine and pyridine-4-formaldhyde. The tetranuclear [Cu4(L1)2Cl2]2+ moiety displays McClellan Saddle-like configuration. Reaction of Cu(BF4)2⋅6H2O with 1, 1΄-(pyridin-4-ylmethylene)bis(3-(pyridin-2-yl)imidazo[1, 5-a]pyridine (L2) in glass tube generated [Cu(L2)(H2O)2]2[BF4]2(SiF6)⋅2H2O (2). The structures of 1 and 2 were characterized by X-ray single-crystal diffraction analysis. The catalytic activities of 1 and 2 toward ketalization reactions were studied. They both exhibited high activities for the ketalization of aliphatic ketones by ethylene glycol.
The syntheses, crystal structures and catalytic activities of two copper complexes are reported. Reaction of CuCl, 3-(pyridin-2-yl)imidazo[1, 5-a]pyridine and pyridine-4-formaldehyde under solvothermal conditions gave [Cu4(L1)2Cl2][CuCl2]2 (1, L1 = 1, 1΄-(pyridin-4-ylmethylene)bis(3-(pyridin-2-yl)imidazo[1, 5-a]pyridine). The ligand L1 was generated in situ from the reaction of 3-(pyridin-2-yl)imidazo[1, 5-a]pyridine and pyridine-4-formaldhyde. The tetranuclear [Cu4(L1)2Cl2]2+ moiety displays McClellan Saddle-like configuration. Reaction of Cu(BF4)2⋅6H2O with 1, 1΄-(pyridin-4-ylmethylene)bis(3-(pyridin-2-yl)imidazo[1, 5-a]pyridine (L2) in glass tube generated [Cu(L2)(H2O)2]2[BF4]2(SiF6)⋅2H2O (2). The structures of 1 and 2 were characterized by X-ray single-crystal diffraction analysis. The catalytic activities of 1 and 2 toward ketalization reactions were studied. They both exhibited high activities for the ketalization of aliphatic ketones by ethylene glycol.
2020, 39(6): 1063-1069
doi: 10.14102/j.cnki.0254-5861.2011-2551
Abstract:
In this text, we present researches on the synthesis of polyoxo-titanium clusters (PTCs) by the use of gadolinium pivalate precursor. During the synthesis process, we discover that solvents play an important role. When acetonitrile was used as solvent, Ti8Gd(μ2-O)(μ3-O)5(Sal)5(OPiv)2(μ2-OiPr)3(μ-OiPr)8 (PTC-82) (H2Sal = salicylic acid, HOPiv = pivalic acid) was obtained. When N, N-dimethylformamide (DMF) was used as solvent under the same reaction conditions, Ti4Gd2(μ3-O)2(Sal)4(OPiv)4(μ2-OiPr)2(μ-OiPr)4(DMF)2 (PTC-83) was synthesized. The solid-state UV absorption spectra revealed that the dopant of lanthanide and the incorporation of salicylic acid ligands have successfully narrowed the bandgap of PTCs. In addition, they exhibited rapid and reproducible photo-responses.
In this text, we present researches on the synthesis of polyoxo-titanium clusters (PTCs) by the use of gadolinium pivalate precursor. During the synthesis process, we discover that solvents play an important role. When acetonitrile was used as solvent, Ti8Gd(μ2-O)(μ3-O)5(Sal)5(OPiv)2(μ2-OiPr)3(μ-OiPr)8 (PTC-82) (H2Sal = salicylic acid, HOPiv = pivalic acid) was obtained. When N, N-dimethylformamide (DMF) was used as solvent under the same reaction conditions, Ti4Gd2(μ3-O)2(Sal)4(OPiv)4(μ2-OiPr)2(μ-OiPr)4(DMF)2 (PTC-83) was synthesized. The solid-state UV absorption spectra revealed that the dopant of lanthanide and the incorporation of salicylic acid ligands have successfully narrowed the bandgap of PTCs. In addition, they exhibited rapid and reproducible photo-responses.
2020, 39(6): 1070-1076
doi: 10.14102/j.cnki.0254-5861.2011-2659
Abstract:
A new binuclear cobalt(Ⅱ) complex, [Co2(C10H6NO2)2(C12H8N2)2(N3)2]·H2O (1, C10H6NO2-: isoquinoline-1-carboxylate, C12H8N2: 1, 10-phenanthroline (phen); N3-: azide), has been synthesized though a mixed-solvothermal method using the pentanol and distilled water as solvent. The complex was characterized by elemental analysis, IR spectrum and single-crystal X-ray diffraction. It crystallizes in triclinic system, space group P\begin{document}$ \overline 1 $\end{document}
A new binuclear cobalt(Ⅱ) complex, [Co2(C10H6NO2)2(C12H8N2)2(N3)2]·H2O (1, C10H6NO2-: isoquinoline-1-carboxylate, C12H8N2: 1, 10-phenanthroline (phen); N3-: azide), has been synthesized though a mixed-solvothermal method using the pentanol and distilled water as solvent. The complex was characterized by elemental analysis, IR spectrum and single-crystal X-ray diffraction. It crystallizes in triclinic system, space group P
2020, 39(6): 1077-1086
doi: 10.14102/j.cnki.0254-5861.2011-2656
Abstract:
Two new low-dimensional Mn(Ⅱ) coordination compounds of Mn(H2pimdc)2(phen) (compound 1) and [Mn(Hpimdc)(phen)]n·nH2O (compound 2) were synthesized, where H3pimdc is a 2-propyl-imidazole-4, 5-dicarboxylic acid and phen is 1, 10-phenanthroline. Both compounds were thoroughly analyzed by X-ray single-crystal diffraction, element analysis, IR spectra, PXRD and thermal analysis. X-ray single-crystal diffraction analyses indicate that the phen ligands terminate metal ions on two sides to prevent the linkage between the neighboring metal ions into a higher dimensional structure in compounds 1 and 2. Compound 1 is constructed from mononuclear molecules which form the 1D helical supramolecular chain by N–H···O hydrogen bonds. In compound 2, Hpimdc is a tetradentate bridging ligand, which binds Mn(Ⅱ) ions to generate a single-stranded right helical chain parallel to the b axis. These 1D chains are additionally coupled by H-bonds as well as π···π stacking interactions, which formed a 3D supramolecular structure. Additionally, compound 2 demonstrated temperature-dependent magnetic susceptibility and negative value of θ (equal to –9.09 K), which is indicative of weak antiferromagnetic interactions between Mn(Ⅱ) ions.
Two new low-dimensional Mn(Ⅱ) coordination compounds of Mn(H2pimdc)2(phen) (compound 1) and [Mn(Hpimdc)(phen)]n·nH2O (compound 2) were synthesized, where H3pimdc is a 2-propyl-imidazole-4, 5-dicarboxylic acid and phen is 1, 10-phenanthroline. Both compounds were thoroughly analyzed by X-ray single-crystal diffraction, element analysis, IR spectra, PXRD and thermal analysis. X-ray single-crystal diffraction analyses indicate that the phen ligands terminate metal ions on two sides to prevent the linkage between the neighboring metal ions into a higher dimensional structure in compounds 1 and 2. Compound 1 is constructed from mononuclear molecules which form the 1D helical supramolecular chain by N–H···O hydrogen bonds. In compound 2, Hpimdc is a tetradentate bridging ligand, which binds Mn(Ⅱ) ions to generate a single-stranded right helical chain parallel to the b axis. These 1D chains are additionally coupled by H-bonds as well as π···π stacking interactions, which formed a 3D supramolecular structure. Additionally, compound 2 demonstrated temperature-dependent magnetic susceptibility and negative value of θ (equal to –9.09 K), which is indicative of weak antiferromagnetic interactions between Mn(Ⅱ) ions.
2020, 39(6): 1087-1092
doi: 10.14102/j.cnki.0254-5861.2011-2799
Abstract:
A new terbium(Ⅲ) complex Tb2(C15H11O3)6(phen)2 has been synthesized with 2-(4-methylben-zoyl)benzoic acid and 1, 10-phenanthroline as ligands. Crystal data for the complex are as follows: monoclinic, space group P21/n, a = 15.0786(6), b = 13.5762(5), c = 22.9683(9) Å, β = 104.130(4)º, V = 4559.6(3) Å3, Dc = 1.540 g/cm3, Z = 2, μ(MoKα) = 1.615 mm–1, F(000) = 2136, the final R = 0.0528 and wR = 0.0740. The Tb(Ⅲ) ion is coordinated by eight atoms to give a distorted square antiprism coordination geometry. The complex shows four fluorescence emission bands arising from the transitions of Tb3+: 5D4 → 7F6 (490 nm), 5D4 → 7F5 (546 nm), 5D4 → 7F4 (588 nm) and 5D4 → 7F3 (622 nm). The complex is an antiferromagnet in the range of 300~2 K. Also reported in the paper is the thermal stability property of the title complex.
A new terbium(Ⅲ) complex Tb2(C15H11O3)6(phen)2 has been synthesized with 2-(4-methylben-zoyl)benzoic acid and 1, 10-phenanthroline as ligands. Crystal data for the complex are as follows: monoclinic, space group P21/n, a = 15.0786(6), b = 13.5762(5), c = 22.9683(9) Å, β = 104.130(4)º, V = 4559.6(3) Å3, Dc = 1.540 g/cm3, Z = 2, μ(MoKα) = 1.615 mm–1, F(000) = 2136, the final R = 0.0528 and wR = 0.0740. The Tb(Ⅲ) ion is coordinated by eight atoms to give a distorted square antiprism coordination geometry. The complex shows four fluorescence emission bands arising from the transitions of Tb3+: 5D4 → 7F6 (490 nm), 5D4 → 7F5 (546 nm), 5D4 → 7F4 (588 nm) and 5D4 → 7F3 (622 nm). The complex is an antiferromagnet in the range of 300~2 K. Also reported in the paper is the thermal stability property of the title complex.
2020, 39(6): 1093-1102
doi: 10.14102/j.cnki.0254-5861.2011-2548
Abstract:
In order to study the influence of substituents on imino-aryl rings of mono(imino)pyrrole-transition metal complexes to their ethylene polymerization performance, a series of mono(imine)pyrroles (L1-L3) were synthesized by microwave irradiation from 2-acetylpyrrole and a series of 2, 6-position disubstituted anilines (substituent: H, Me, Et). A simplified synthetic method was introduced to prepare the corresponding nickel complexes NiL2 (1~3) with direct condensation of mono(imine)pyrrole ligands and nickel dichloride. All the compounds were fully characterized by 1H NMR, IR, EA, MS, and X-ray crystal diffraction. Ligand L3 (C16H20N2, Mr = 240.34) belongs to the triclinic system, space group P\begin{document}$ \overline 1 $\end{document}
In order to study the influence of substituents on imino-aryl rings of mono(imino)pyrrole-transition metal complexes to their ethylene polymerization performance, a series of mono(imine)pyrroles (L1-L3) were synthesized by microwave irradiation from 2-acetylpyrrole and a series of 2, 6-position disubstituted anilines (substituent: H, Me, Et). A simplified synthetic method was introduced to prepare the corresponding nickel complexes NiL2 (1~3) with direct condensation of mono(imine)pyrrole ligands and nickel dichloride. All the compounds were fully characterized by 1H NMR, IR, EA, MS, and X-ray crystal diffraction. Ligand L3 (C16H20N2, Mr = 240.34) belongs to the triclinic system, space group P
2020, 39(6): 1103-1111
doi: 10.14102/j.cnki.0254-5861.2011-2601
Abstract:
Two novel macrocyclic Schiff base complexes [LnL(PhCOO)(CH3OH)](ClO4)2·(CH3OH)2 (Ln = Ho, 1; Ln = Er, 2), in which L denotes the macrocyclic ligand, were synthesized via condensation of 2, 6-diformyl-4-methyl-phenol and 1, 3-diamino-2-propanol by employing benzoate as the second ligand. Their crystal structures were determined by X-ray diffraction, which showed that both complexes belong to a monoclinic system with space group P21/c. The coordination polyhedron displayed a distorted bicapped trigonal prism with the coordination number of eight. Both complexes efficiently cleaved supercoiled DNA to its nicked circular form. The UV-vis absorption results and ethidium bromide (EB) fluorescence spectra indicated that the complexes bind to CT-DNA in an intercalative mode, with Ksq values to be 11830 and 10560, respectively.
Two novel macrocyclic Schiff base complexes [LnL(PhCOO)(CH3OH)](ClO4)2·(CH3OH)2 (Ln = Ho, 1; Ln = Er, 2), in which L denotes the macrocyclic ligand, were synthesized via condensation of 2, 6-diformyl-4-methyl-phenol and 1, 3-diamino-2-propanol by employing benzoate as the second ligand. Their crystal structures were determined by X-ray diffraction, which showed that both complexes belong to a monoclinic system with space group P21/c. The coordination polyhedron displayed a distorted bicapped trigonal prism with the coordination number of eight. Both complexes efficiently cleaved supercoiled DNA to its nicked circular form. The UV-vis absorption results and ethidium bromide (EB) fluorescence spectra indicated that the complexes bind to CT-DNA in an intercalative mode, with Ksq values to be 11830 and 10560, respectively.
2020, 39(6): 1112-1118
doi: 10.14102/j.cnki.0254-5861.2011-2606
Abstract:
A new di-nuclear ruthenium arene compound containing thiosemicarbazone ligands, [Ru(η6-cymene)(TSC)Cl]2(PF6)2 (2), was synthesized and characterized by 1H NMR, HR-ESI-MS, and elemental analysis. Furthermore, the complete structure of 2 was determined by single-crystal X-ray diffraction analysis. Density functional theory (DFT) calculations with B3LYP functional and LANL2DZ (for Ru)/6-31G* (for other atoms) basis sets were carried out for the reactions involving complexes 1 and 2 in order to understand the formation of the complexes. The in vitro anticancer activities of the compound were investigated against five human cancer cell lines (SGC-7901, CNE-2, HepG2, KB and HeLa), and the IC50 values are 39.5, 45.8, 49.8, 54.5 and 61.8 μM, respectively.
A new di-nuclear ruthenium arene compound containing thiosemicarbazone ligands, [Ru(η6-cymene)(TSC)Cl]2(PF6)2 (2), was synthesized and characterized by 1H NMR, HR-ESI-MS, and elemental analysis. Furthermore, the complete structure of 2 was determined by single-crystal X-ray diffraction analysis. Density functional theory (DFT) calculations with B3LYP functional and LANL2DZ (for Ru)/6-31G* (for other atoms) basis sets were carried out for the reactions involving complexes 1 and 2 in order to understand the formation of the complexes. The in vitro anticancer activities of the compound were investigated against five human cancer cell lines (SGC-7901, CNE-2, HepG2, KB and HeLa), and the IC50 values are 39.5, 45.8, 49.8, 54.5 and 61.8 μM, respectively.
2020, 39(6): 1119-1125
doi: 10.14102/j.cnki.0254-5861.2011-2558
Abstract:
Novel organic compounds (1~8) were designed, synthesized and characterized by IR, 1H NMR, H RMS, and single-crystal X-ray crystallography. The anticancer activities of these compounds were investigated against four human lung cancer cells (H20, H2227, H69 and H524) by 3-(4, 5)-dimethylthiahiazo(-z-y1)-3, 5-di-phenytetrazoliumromide (MTT) assay. Furthermore, by taking compounds 1 and 5 as representatives, molecular docking studies supported the biological assay data, suggesting that compared with 1, compound 5 has stronger interaction with protein.
Novel organic compounds (1~8) were designed, synthesized and characterized by IR, 1H NMR, H RMS, and single-crystal X-ray crystallography. The anticancer activities of these compounds were investigated against four human lung cancer cells (H20, H2227, H69 and H524) by 3-(4, 5)-dimethylthiahiazo(-z-y1)-3, 5-di-phenytetrazoliumromide (MTT) assay. Furthermore, by taking compounds 1 and 5 as representatives, molecular docking studies supported the biological assay data, suggesting that compared with 1, compound 5 has stronger interaction with protein.
2020, 39(6): 1126-1134
doi: 10.14102/j.cnki.0254-5861.2011-2653
Abstract:
Unexpected transition metal (TM)-π interaction enhanced fluorescence in Cu-π-diborene complexes is a novel phenomenon compared with other metal enhanced fluorescence. In order to discover the mechanism, theoretical investigation was carried out for Cu-π-diborene as well as diborene. Simulation results show the main decay method in diborene and Cu-π-diborene are internal conversion (IC) and fluorescence (FL), respectively. TM-π interaction leads to larger HOMO-LUMO gap of Cu-π-diborene than that of the free diborene, which results in lower IC rates and makes them smaller than the FL rates. At the same time, ISC rates are always smaller than IC and FL rates, which cause enhanced fluorescence of Cu-π-diborene. More interestingly, even though Cu-π-diborene shows enhanced fluorescence, intersystem crossing (ISC) in Cu-π-diborene is enhanced from diborene. The theoretical analysis shows the competition among IC, FL and ISC is the key factor for TM-π interactions enhanced fluorescence, which also shows that cation-π complexes have potential to be used as luminescent probes.
Unexpected transition metal (TM)-π interaction enhanced fluorescence in Cu-π-diborene complexes is a novel phenomenon compared with other metal enhanced fluorescence. In order to discover the mechanism, theoretical investigation was carried out for Cu-π-diborene as well as diborene. Simulation results show the main decay method in diborene and Cu-π-diborene are internal conversion (IC) and fluorescence (FL), respectively. TM-π interaction leads to larger HOMO-LUMO gap of Cu-π-diborene than that of the free diborene, which results in lower IC rates and makes them smaller than the FL rates. At the same time, ISC rates are always smaller than IC and FL rates, which cause enhanced fluorescence of Cu-π-diborene. More interestingly, even though Cu-π-diborene shows enhanced fluorescence, intersystem crossing (ISC) in Cu-π-diborene is enhanced from diborene. The theoretical analysis shows the competition among IC, FL and ISC is the key factor for TM-π interactions enhanced fluorescence, which also shows that cation-π complexes have potential to be used as luminescent probes.
2020, 39(6): 1135-1145
doi: 10.14102/j.cnki.0254-5861.2011-2539
Abstract:
In this paper, 42 4-hydroxyamino α-pyranone carboxamide analogues as Hepatitis C Virus (HCV) inhibitor 3D-QSAR model was built based on Topomer CoMFA. The non-cross-validation (r2), cross-validation (q2), correlation coefficient of external validation (Qext2), non-cross validated standard error (SD), standard error of prediction (SDCV) and F are 0.909, 0.615, 0.967, 0.13, 0.28 and 37.287, respectively. The obtained Topomer CoMFA model has good estimation stability and prediction capability. Topomer Search was employed as a tool for virtual screening in lead-like compounds in the ZINC database. Then, 6 R1 groups and 4 R2 groups with higher contribution values were employed to alternately substitute for the R1 and R2 of the template compound 21 with the highest bioactivity. As a result, 22 new molecules with higher activity than that of the template molecule were designed successfully. The Topomer Search technology could be effectively applied to screen and design new 4-hydroxyamino α-pyranone carboxamide analogues. The molecular docking method was also used to study the interactions of these drugs by docking the ligands into HCV active site, which revealed the likely bioactive conformations. This study showed extensive interactions between the 4-hydroxyamino α-pyranone carboxamide analogues and the active sites of HCV (residues TYR466, GLN384, TYR383 and ASP335). The design of potent new inhibitors of HCV can get useful insights from these results.
In this paper, 42 4-hydroxyamino α-pyranone carboxamide analogues as Hepatitis C Virus (HCV) inhibitor 3D-QSAR model was built based on Topomer CoMFA. The non-cross-validation (r2), cross-validation (q2), correlation coefficient of external validation (Qext2), non-cross validated standard error (SD), standard error of prediction (SDCV) and F are 0.909, 0.615, 0.967, 0.13, 0.28 and 37.287, respectively. The obtained Topomer CoMFA model has good estimation stability and prediction capability. Topomer Search was employed as a tool for virtual screening in lead-like compounds in the ZINC database. Then, 6 R1 groups and 4 R2 groups with higher contribution values were employed to alternately substitute for the R1 and R2 of the template compound 21 with the highest bioactivity. As a result, 22 new molecules with higher activity than that of the template molecule were designed successfully. The Topomer Search technology could be effectively applied to screen and design new 4-hydroxyamino α-pyranone carboxamide analogues. The molecular docking method was also used to study the interactions of these drugs by docking the ligands into HCV active site, which revealed the likely bioactive conformations. This study showed extensive interactions between the 4-hydroxyamino α-pyranone carboxamide analogues and the active sites of HCV (residues TYR466, GLN384, TYR383 and ASP335). The design of potent new inhibitors of HCV can get useful insights from these results.
2020, 39(6): 1146-1156
doi: 10.14102/j.cnki.0254-5861.2011-2538
Abstract:
Dimethyldichlorosilane is a basic raw material for preparing a variety of organosilicon materials. The disproportionation method to synthesize it can solve the problem brought by direct synthesis. The B3LYP/6-31G and MP2/6-311++ G(3df, 2pd) methods were used to calculate the mechanism of the reaction catalyzed by localized core(4T)-shell catalyst. The energy barriers of the rate-determining steps of the main reaction at different active sites 1(5)~4 in the HZSM-5(4T)@γ-Al2O3 catalyst were 165.88, 129.99, 118.66 and 145.55 kJ⋅mol-1, respectively, and those in the side reaction are 131.98, 146.28, 146.53 and 164.17 kJ⋅mol-1, separately. The active site No. 3 was the easiest one to participate in the catalytic reaction. The energy barriers of the rate-determining steps of the main reaction catalyzed by the AlCl3/HZSM-5(4T)@γ-Al2O3 catalyst, involving configurations a and b, are 105.12 and 110.39 kJ⋅mol-1, respectively, and those of the side reaction are 144.26 and 159.55 kJ⋅mol-1, respectively. Both configurations produced dimethyldichlorosilane mainly, and configuration a is easier to catalyze the reaction process. And according to the bond order and locality analysis, the catalytic activity order was: configuration a > configuration b. This conclusion matched with the reaction energy barrier analysis. The AlCl3/HZSM-5(4T)@γ-Al2O3 catalyst had a better catalytic activity than HZSM-5(4T)@γ-Al2O3. The active center of the reaction system of HZSM-5(4T)@γ-Al2O3 was proton, Bronsted acidic center, and that of AlCl3/HZSM-5@γ-Al2O3 could be Lewis acidic center. The source of the Lewis acidic center was the multi-center bond formed by the delocalization of peripheral electrons of the atoms. The frontier orbital theory confirmed the mechanism and good selectivity of the reaction.
Dimethyldichlorosilane is a basic raw material for preparing a variety of organosilicon materials. The disproportionation method to synthesize it can solve the problem brought by direct synthesis. The B3LYP/6-31G and MP2/6-311++ G(3df, 2pd) methods were used to calculate the mechanism of the reaction catalyzed by localized core(4T)-shell catalyst. The energy barriers of the rate-determining steps of the main reaction at different active sites 1(5)~4 in the HZSM-5(4T)@γ-Al2O3 catalyst were 165.88, 129.99, 118.66 and 145.55 kJ⋅mol-1, respectively, and those in the side reaction are 131.98, 146.28, 146.53 and 164.17 kJ⋅mol-1, separately. The active site No. 3 was the easiest one to participate in the catalytic reaction. The energy barriers of the rate-determining steps of the main reaction catalyzed by the AlCl3/HZSM-5(4T)@γ-Al2O3 catalyst, involving configurations a and b, are 105.12 and 110.39 kJ⋅mol-1, respectively, and those of the side reaction are 144.26 and 159.55 kJ⋅mol-1, respectively. Both configurations produced dimethyldichlorosilane mainly, and configuration a is easier to catalyze the reaction process. And according to the bond order and locality analysis, the catalytic activity order was: configuration a > configuration b. This conclusion matched with the reaction energy barrier analysis. The AlCl3/HZSM-5(4T)@γ-Al2O3 catalyst had a better catalytic activity than HZSM-5(4T)@γ-Al2O3. The active center of the reaction system of HZSM-5(4T)@γ-Al2O3 was proton, Bronsted acidic center, and that of AlCl3/HZSM-5@γ-Al2O3 could be Lewis acidic center. The source of the Lewis acidic center was the multi-center bond formed by the delocalization of peripheral electrons of the atoms. The frontier orbital theory confirmed the mechanism and good selectivity of the reaction.
2020, 39(6): 1157-1166
doi: 10.14102/j.cnki.0254-5861.2011-2545
Abstract:
The three-dimensional quantitative structure-activity relationships (3D-QSAR) for 37 curcumin derivatives were constructed by CoMFA and CoMSIA methods, respectively. The results showed that the cross validated coefficient (q2) and non-cross-validated coefficient (R2) were 0.711, 0.962 in CoMFA model and 0.774, 0.856 in CoMSIA model, respectively, which suggests that two models are robust and have good exterior predictive capabilities. Based on these two models and the binding mode with tubulin, nine novel curcuminoids inhibitors which could exhibit much higher anticancer potency and efficiently occupy the colchicine binding site of tubulin, were designed. We expect that the results in this paper have the potential to facilitate the process of design and to develop new potent curcumin derivatives with stronger anticancer activities.
The three-dimensional quantitative structure-activity relationships (3D-QSAR) for 37 curcumin derivatives were constructed by CoMFA and CoMSIA methods, respectively. The results showed that the cross validated coefficient (q2) and non-cross-validated coefficient (R2) were 0.711, 0.962 in CoMFA model and 0.774, 0.856 in CoMSIA model, respectively, which suggests that two models are robust and have good exterior predictive capabilities. Based on these two models and the binding mode with tubulin, nine novel curcuminoids inhibitors which could exhibit much higher anticancer potency and efficiently occupy the colchicine binding site of tubulin, were designed. We expect that the results in this paper have the potential to facilitate the process of design and to develop new potent curcumin derivatives with stronger anticancer activities.
2020, 39(6): 1167-1177
doi: 10.14102/j.cnki.0254-5861.2011-2543
Abstract:
The wide use of quaternary ammonium cationic surfactants (QACs) results in their release into the environment. Most surfactants have significant biotoxicity. However, existing toxicity data on QACs are still lacking, especially regarding the joint toxic effects of their mixtures. In computer simulation technology, molecular docking technology is commonly used for studying the mode of action of receptors docking with ligands. The research of QACs mixture interaction is relatively rare, and the binding mode of QACs is unknown. In this study, molecular docking technology was applied to explore the QAC binding mode, and the concentration addition (CA) and independent action (IA) models were applied for predicting the mixture toxicity. Firefly luciferase (FLuc) was used as a macromolecular receptor, and five typical QACs: benzalkonium bromide (BLB), tetraethylammonium bromide (TLB), N, N, N-trimethyl-1-tetradecyl ammonium bromide (CTE), tetrabutylammonium chloride (TAC), and dodecyltrimethylammonium chloride (DTC) were used as small molecule ligands. Molecular docking technology was used to investigate the binding mode of macromolecules and small molecules. The luminescence inhibitory effects of individual compounds and binary mixture on FLuc were determined by microplate toxicity assay of luciferase. The prediction of mixture toxicity was performed by CA and IA. The results showed that the relative toxicity follows: TLB < TAC < DTC < BLB < CTE. TLB and TAC showed the BS-Ⅱ binding mode, and BLB, CTE and DTC showed the BS-Ⅲ binding mode. The toxicity of compounds with binding mode BS-Ⅱ was less than that of those with BS-Ⅲ binding mode. Not all mixtures with the same binding mode could be predicted by CA model, and the IA model did not effectively predict the toxicity of mixtures with compound with different binding modes. The mixture toxicities of QACs with the same binding mode mostly presented additive and synergistic effects, while the mixture toxic effects of QACs with different binding modes presented additive or antagonistic effects.
The wide use of quaternary ammonium cationic surfactants (QACs) results in their release into the environment. Most surfactants have significant biotoxicity. However, existing toxicity data on QACs are still lacking, especially regarding the joint toxic effects of their mixtures. In computer simulation technology, molecular docking technology is commonly used for studying the mode of action of receptors docking with ligands. The research of QACs mixture interaction is relatively rare, and the binding mode of QACs is unknown. In this study, molecular docking technology was applied to explore the QAC binding mode, and the concentration addition (CA) and independent action (IA) models were applied for predicting the mixture toxicity. Firefly luciferase (FLuc) was used as a macromolecular receptor, and five typical QACs: benzalkonium bromide (BLB), tetraethylammonium bromide (TLB), N, N, N-trimethyl-1-tetradecyl ammonium bromide (CTE), tetrabutylammonium chloride (TAC), and dodecyltrimethylammonium chloride (DTC) were used as small molecule ligands. Molecular docking technology was used to investigate the binding mode of macromolecules and small molecules. The luminescence inhibitory effects of individual compounds and binary mixture on FLuc were determined by microplate toxicity assay of luciferase. The prediction of mixture toxicity was performed by CA and IA. The results showed that the relative toxicity follows: TLB < TAC < DTC < BLB < CTE. TLB and TAC showed the BS-Ⅱ binding mode, and BLB, CTE and DTC showed the BS-Ⅲ binding mode. The toxicity of compounds with binding mode BS-Ⅱ was less than that of those with BS-Ⅲ binding mode. Not all mixtures with the same binding mode could be predicted by CA model, and the IA model did not effectively predict the toxicity of mixtures with compound with different binding modes. The mixture toxicities of QACs with the same binding mode mostly presented additive and synergistic effects, while the mixture toxic effects of QACs with different binding modes presented additive or antagonistic effects.
