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2011 Volume 22 Issue 9
2011, 22(9): 1009-1012
doi: 10.1016/j.cclet.2011.01.042
Abstract:
A new synthesis of spirocyclic oxindole analogue spirofpiperidine-4, 3'-pyrrolo[2, 3-b]pyridin]-2' (1'H)-one 1 is described. The key steps involve dialkylation of arylacetonitrile and cyclization of the azaoxindole ring by an intramolecular Buchwald-Hartwig amidation of carboxylic amide and aryl chloride. A small library was obtained by reductive amination of 1 with various aldehydes and was screened against human lung cancer cell A549, human liver cancer cell BEL7402, and human colon cancer cell HCT-8. The results show that most of the library compounds 2 have some inhibitory activities. 2- (Trifluoromethoxy) benzylic substituted spirocyclic azaoxindole 2e was identified as a nanomolar inhibitor against human lung cancer cell A-549 (IC50=50 nmol/L).
A new synthesis of spirocyclic oxindole analogue spirofpiperidine-4, 3'-pyrrolo[2, 3-b]pyridin]-2' (1'H)-one 1 is described. The key steps involve dialkylation of arylacetonitrile and cyclization of the azaoxindole ring by an intramolecular Buchwald-Hartwig amidation of carboxylic amide and aryl chloride. A small library was obtained by reductive amination of 1 with various aldehydes and was screened against human lung cancer cell A549, human liver cancer cell BEL7402, and human colon cancer cell HCT-8. The results show that most of the library compounds 2 have some inhibitory activities. 2- (Trifluoromethoxy) benzylic substituted spirocyclic azaoxindole 2e was identified as a nanomolar inhibitor against human lung cancer cell A-549 (IC50=50 nmol/L).
2011, 22(9): 1013-1016
doi: 10.1016/j.cclet.2011.03.007
Abstract:
A novel fluorescent Zn2+ probe based on 6-methoxyquinolin was synthesized in four steps from inexpensive starting materials. It exhibits very strong fluorescence responses and has a remarkably high selectivity to Zn2+ than other physiological relevant metal ions. This new compound could be used as low-priced yet high-quality Zn2+ probe.
A novel fluorescent Zn2+ probe based on 6-methoxyquinolin was synthesized in four steps from inexpensive starting materials. It exhibits very strong fluorescence responses and has a remarkably high selectivity to Zn2+ than other physiological relevant metal ions. This new compound could be used as low-priced yet high-quality Zn2+ probe.
2011, 22(9): 1017-1020
doi: 10.1016/j.cclet.2011.05.008
Abstract:
Two new functional polyacetylenes bearing carbazole group as pendant, poly {3-[(4-ethynylstyryl)-N-butyl] carbazole} (P1) and poly{3-[4- (prop-2-ynyloxy)phenyl-N-butyl]carbazole) (P2), were prepared using[Rh (nbd)Cl]2-Et3N as catalyst. The polymers were soluble in common organic solvents such as CHCl3 and THF. Their structures and properties were characterized and evaluated with FTIR, 1H NMR, UV, TGA, GPC, and CV, respectively. The results show that the polymers possess high thermal stability and well hole-injection property.
Two new functional polyacetylenes bearing carbazole group as pendant, poly {3-[(4-ethynylstyryl)-N-butyl] carbazole} (P1) and poly{3-[4- (prop-2-ynyloxy)phenyl-N-butyl]carbazole) (P2), were prepared using[Rh (nbd)Cl]2-Et3N as catalyst. The polymers were soluble in common organic solvents such as CHCl3 and THF. Their structures and properties were characterized and evaluated with FTIR, 1H NMR, UV, TGA, GPC, and CV, respectively. The results show that the polymers possess high thermal stability and well hole-injection property.
2011, 22(9): 1021-1024
doi: 10.1016/j.cclet.2011.03.014
Abstract:
By using the famous Wilkinson's catalyst, N-alkylation of sulfonamides can be easily realized under mild aerobic conditions by using alcohols as the alkylating reagent, giving monoalkylated sulfonamides in high yields and selectivities with water produced as the only byproduct. This advantageous aerobic method is potentially general in substrate scope that it can also be applied to other amides, amines and alcohols.
By using the famous Wilkinson's catalyst, N-alkylation of sulfonamides can be easily realized under mild aerobic conditions by using alcohols as the alkylating reagent, giving monoalkylated sulfonamides in high yields and selectivities with water produced as the only byproduct. This advantageous aerobic method is potentially general in substrate scope that it can also be applied to other amides, amines and alcohols.
2011, 22(9): 1025-1028
doi: 10.1016/j.cclet.2011.04.001
Abstract:
Three novel bis-chalcone derivatives with different alkyldioxy spacers were synthesized and dispersed into polymethyl methacrylate (PMMA) chloroform solution with 6-nitro-1'-ethyl-3', 3'-dimethylspiro-2H-1-benzopyran-2, 2'-indoline (ESP) to prepare photochromic PMMA films in a facile way. After irradiation with 365 nm UV light, the photocrosslinking reaction between chalcone units was proved to retard the decolorization of merocyanine form of the photochromic spiropyran effectively, as results of the steric hindrance produced by photocycloaddition of chalcone groups. It has been found that the bis-chalcone molecule with the shortest spacer has the most effective stabilizing effect on retardation of decoloration of spiropyran.
Three novel bis-chalcone derivatives with different alkyldioxy spacers were synthesized and dispersed into polymethyl methacrylate (PMMA) chloroform solution with 6-nitro-1'-ethyl-3', 3'-dimethylspiro-2H-1-benzopyran-2, 2'-indoline (ESP) to prepare photochromic PMMA films in a facile way. After irradiation with 365 nm UV light, the photocrosslinking reaction between chalcone units was proved to retard the decolorization of merocyanine form of the photochromic spiropyran effectively, as results of the steric hindrance produced by photocycloaddition of chalcone groups. It has been found that the bis-chalcone molecule with the shortest spacer has the most effective stabilizing effect on retardation of decoloration of spiropyran.
2011, 22(9): 1029-1032
doi: 10.1016/j.cclet.2011.03.015
Abstract:
Aromatic aldehydes undergo crossed-aldol condensation with ketones in the presence of catalytic amount of sulfamic acid (SA) to afford the corresponding α, β-unsaturated aldol products under solvent-free conditions in good to high yields at 45-80℃.
Aromatic aldehydes undergo crossed-aldol condensation with ketones in the presence of catalytic amount of sulfamic acid (SA) to afford the corresponding α, β-unsaturated aldol products under solvent-free conditions in good to high yields at 45-80℃.
2011, 22(9): 1033-1035
doi: 10.1016/j.cclet.2011.01.013
Abstract:
A novel 4-anilinoquinazoline dimer linked by a carbon-carbon bond in the C-7 position was synthesized via a one step Suzuki cross-coupling reaction. All structures of new compounds were characterized by 1H NMR, 13C NMR, and HRMS. The inhibition rate of the synthetic 4-anilinoquinazoline dimer 8 against epidermal growth factor receptor-tyrosine kinase enzymes (EGFR) in vitro was 44.4% at the concentration of 5.5 μmol/L.
A novel 4-anilinoquinazoline dimer linked by a carbon-carbon bond in the C-7 position was synthesized via a one step Suzuki cross-coupling reaction. All structures of new compounds were characterized by 1H NMR, 13C NMR, and HRMS. The inhibition rate of the synthetic 4-anilinoquinazoline dimer 8 against epidermal growth factor receptor-tyrosine kinase enzymes (EGFR) in vitro was 44.4% at the concentration of 5.5 μmol/L.
2011, 22(9): 1036-1038
doi: 10.1016/j.cclet.2011.05.012
Abstract:
A facile microwave-assisted procedure for synthesis of novel fluorinated pyrazolo[3, 4-d]pyrimidine derivatives containing 1, 3, 4-thiadiazole is described. This protocol presented such advantages as short reaction time, high yields, simple purification and environmentally benign procedures. Their antitumor activities were evaluated against HL-60 by an MTT assay. The preliminary results indicated that some title compounds exhibit more potent antitumor inhibitory activity than doxorubicin (DOX).
A facile microwave-assisted procedure for synthesis of novel fluorinated pyrazolo[3, 4-d]pyrimidine derivatives containing 1, 3, 4-thiadiazole is described. This protocol presented such advantages as short reaction time, high yields, simple purification and environmentally benign procedures. Their antitumor activities were evaluated against HL-60 by an MTT assay. The preliminary results indicated that some title compounds exhibit more potent antitumor inhibitory activity than doxorubicin (DOX).
2011, 22(9): 1039-1042
doi: 10.1016/j.cclet.2011.03.016
Abstract:
The regiospecific oxidation of alkyl group of both sterically hindered and unhindered aromatic amine to corresponding carbonyl compound was done in aq. medium by using DDQ. The optimized reaction protocol was found to be most simple, high yielding and novel method for oxidation of alkyl group of aromatic amine in to its carbonyl compound.
The regiospecific oxidation of alkyl group of both sterically hindered and unhindered aromatic amine to corresponding carbonyl compound was done in aq. medium by using DDQ. The optimized reaction protocol was found to be most simple, high yielding and novel method for oxidation of alkyl group of aromatic amine in to its carbonyl compound.
2011, 22(9): 1043-1046
doi: 10.1016/j.cclet.2011.03.009
Abstract:
Formamidine derivatives could be used as the building blocks for substituted heterocyclic compounds with various biological activities. N'-Aryl-N, N-dimethylformamidinium chlorides have been synthesized in high yields by reaction of aromatic primary amines with Vilsmeier-Haack reagent at room temperature. The structures of all the new compounds were identified by ESI-MS, IR and NMR spectra. The steric structures of some of these compounds were clarified by X-ray single crystal analysis.
Formamidine derivatives could be used as the building blocks for substituted heterocyclic compounds with various biological activities. N'-Aryl-N, N-dimethylformamidinium chlorides have been synthesized in high yields by reaction of aromatic primary amines with Vilsmeier-Haack reagent at room temperature. The structures of all the new compounds were identified by ESI-MS, IR and NMR spectra. The steric structures of some of these compounds were clarified by X-ray single crystal analysis.
2011, 22(9): 1047-1050
doi: 10.1016/j.cclet.2011.03.017
Abstract:
Dicyclopentyl azodicarboxylate is introduced as a new azo-reagent which can be conveniently prepared in two steps and be used in the Mitsunobu reaction. Though there are no distinct difference of reactivity between DCpAD and DEAD, the former is a more preferable azo-reagent for its stability.
Dicyclopentyl azodicarboxylate is introduced as a new azo-reagent which can be conveniently prepared in two steps and be used in the Mitsunobu reaction. Though there are no distinct difference of reactivity between DCpAD and DEAD, the former is a more preferable azo-reagent for its stability.
2011, 22(9): 1051-1054
doi: 10.1016/j.cclet.2011.03.013
Abstract:
A new two-photon absorption compound, 2-{4-[(dicyanomethylidene-5, 5-dimethylcyclohexl)vinyl]phenyl}imidazo[4, 5-f] [1, 10]phenanthroline (DDVPIP), was synthesized and characterized. The one-photon excited fluorescence (OPRF) and two-photon excited fluorescence (TPEF) of DDVPIP are sensitive to the acid/base of the solution, which are enhanced in basic solution but weakened in acidic solution. Charge-transfer (CT) states of DDVPIP were calculated through theory methods to explain its acid/base-sensitive fluorescent properties.
A new two-photon absorption compound, 2-{4-[(dicyanomethylidene-5, 5-dimethylcyclohexl)vinyl]phenyl}imidazo[4, 5-f] [1, 10]phenanthroline (DDVPIP), was synthesized and characterized. The one-photon excited fluorescence (OPRF) and two-photon excited fluorescence (TPEF) of DDVPIP are sensitive to the acid/base of the solution, which are enhanced in basic solution but weakened in acidic solution. Charge-transfer (CT) states of DDVPIP were calculated through theory methods to explain its acid/base-sensitive fluorescent properties.
2011, 22(9): 1055-1058
doi: 10.1016/j.cclet.2011.03.010
Abstract:
A convenient method for Morita-Baylis-Hillman reaction of arylaldehydes with methyl acrylate has been developed by using fluorous-tag organocatalyst l-[4- (perfluorooctyl)phenyll-3-phenylthiourea and DABCO at room temperature. The fluorous organocatalyst could be recovered from the reaction mixture by fluorous solid-phase extraction (F-SPE) with excellent purity for direct reuse.
A convenient method for Morita-Baylis-Hillman reaction of arylaldehydes with methyl acrylate has been developed by using fluorous-tag organocatalyst l-[4- (perfluorooctyl)phenyll-3-phenylthiourea and DABCO at room temperature. The fluorous organocatalyst could be recovered from the reaction mixture by fluorous solid-phase extraction (F-SPE) with excellent purity for direct reuse.
2011, 22(9): 1059-1062
doi: 10.1016/j.cclet.2011.03.012
Abstract:
An efficient green protocol for the preparation 3, 4, 6-trisubstituted 2-pyridone of employing a condensation reaction of cyanoacetamide and acetylacetone in the presence of KAl (SO4)2·12H2O in water has been described. The present procedure offers advantage such as shorter reaction time, simple workup, and excellent yields.
An efficient green protocol for the preparation 3, 4, 6-trisubstituted 2-pyridone of employing a condensation reaction of cyanoacetamide and acetylacetone in the presence of KAl (SO4)2·12H2O in water has been described. The present procedure offers advantage such as shorter reaction time, simple workup, and excellent yields.
2011, 22(9): 1063-1066
doi: 10.1016/j.cclet.2011.04.004
Abstract:
4-Methylene-1, 3-oxazolidin-2-ones can be synthesized from propargylic alcohols, primary amines and carbon dioxide under supercritical condition in the absence of any additional catalyst and solvent. Various propargylic alcohols and primary amines were examined.
4-Methylene-1, 3-oxazolidin-2-ones can be synthesized from propargylic alcohols, primary amines and carbon dioxide under supercritical condition in the absence of any additional catalyst and solvent. Various propargylic alcohols and primary amines were examined.
2011, 22(9): 1067-1070
doi: 10.1016/j.cclet.2011.05.013
Abstract:
Electrochemical oxidation of 3-methylcatechol as a model compound has been studied in the presence of 1, 10-phenanthroline as a bi-dentate nucleophile in water/acetonitrile (70/30, v/v) solution using cyclic voltammetry and controlled-potential coulometry. The results revealed that anodically generated 3-methylcyclohexa-3, 5-diene-l, 2-dione participates in inter and intramolecular Michael addition reactions with 1, 10-phenanthroline and via an ECEC pathway converts to the corresponding heterocyclic compound. The present work has led to the development of a facile and one-pot method with high atom economy under ambient conditions and in an undivided cell using a carbon electrode.
Electrochemical oxidation of 3-methylcatechol as a model compound has been studied in the presence of 1, 10-phenanthroline as a bi-dentate nucleophile in water/acetonitrile (70/30, v/v) solution using cyclic voltammetry and controlled-potential coulometry. The results revealed that anodically generated 3-methylcyclohexa-3, 5-diene-l, 2-dione participates in inter and intramolecular Michael addition reactions with 1, 10-phenanthroline and via an ECEC pathway converts to the corresponding heterocyclic compound. The present work has led to the development of a facile and one-pot method with high atom economy under ambient conditions and in an undivided cell using a carbon electrode.
2011, 22(9): 1071-1074
doi: 10.1016/j.cclet.2011.04.014
Abstract:
Schiff base-Cu (Ⅱ) complex is found to be an effective catalyst for the condensation reaction of indole with aldehydes using ethanol as the solvent. The characterization of the catalysts was carried out using XRD and FT-IR.
Schiff base-Cu (Ⅱ) complex is found to be an effective catalyst for the condensation reaction of indole with aldehydes using ethanol as the solvent. The characterization of the catalysts was carried out using XRD and FT-IR.
2011, 22(9): 1075-1077
doi: 10.1016/j.cclet.2011.03.004
Abstract:
Two novel 5-methoxydibenzylhydroxybutyrolactone lignans named 5-methoxytracheloside and 5-methoxytrachelogenin were isolated from the stems and leaves of Trachelospermum jasminoides (Lindl. ) Lem., their structures were determined as (8S, 8'S)-8'-hydroxy-3, 3', 4, 5-tetramethoxylignan-9, 9'-olide-4'-O-β-D-glucopyranoside and (8S, 8'S)-4', 8'-dihydroxy-3, 3', 4, 5-tertra-methoxylignan-9, 9'-olide by various spectroscopic analysis. 5-Methoxytracheloside was a new compound and 5-methoxytrachelogenin was isolated from natural source for the first time.
Two novel 5-methoxydibenzylhydroxybutyrolactone lignans named 5-methoxytracheloside and 5-methoxytrachelogenin were isolated from the stems and leaves of Trachelospermum jasminoides (Lindl. ) Lem., their structures were determined as (8S, 8'S)-8'-hydroxy-3, 3', 4, 5-tetramethoxylignan-9, 9'-olide-4'-O-β-D-glucopyranoside and (8S, 8'S)-4', 8'-dihydroxy-3, 3', 4, 5-tertra-methoxylignan-9, 9'-olide by various spectroscopic analysis. 5-Methoxytracheloside was a new compound and 5-methoxytrachelogenin was isolated from natural source for the first time.
2011, 22(9): 1078-1080
doi: 10.1016/j.cclet.2011.04.002
Abstract:
Two new compounds, corialins A (1) and B (2) were isolated from Coriaria nepalensis Wall. These new compounds were established as 7-hydroxy-3-[2, 3-acetonide- (3-methylbutane)] coumarin (1) and 3-O-β-D-glucopyranosyl-3, 4, 5-trihydroxy-1- (3-methyl-2-butenyl)-benzene (2), on the basis of ID and 2D NMR techniques.
Two new compounds, corialins A (1) and B (2) were isolated from Coriaria nepalensis Wall. These new compounds were established as 7-hydroxy-3-[2, 3-acetonide- (3-methylbutane)] coumarin (1) and 3-O-β-D-glucopyranosyl-3, 4, 5-trihydroxy-1- (3-methyl-2-butenyl)-benzene (2), on the basis of ID and 2D NMR techniques.
2011, 22(9): 1081-1083
doi: 10.1016/j.cclet.2011.05.034
Abstract:
A new lignan rhamnoside identified as 2, 6-di (4', 5'-dihydroxyphenyl)-3, 7-dioxabicyclo[3.3.0]octane-1-hydroxy-5-O-rhamno-pyranoside (1) has been isolated from the ethanolic extract of seed pods of Bauhinia retusa. Its structure was established by extensive spectroscopic techniques (UV, IR, ID NMR, 2D NMR, HRESIMS).
A new lignan rhamnoside identified as 2, 6-di (4', 5'-dihydroxyphenyl)-3, 7-dioxabicyclo[3.3.0]octane-1-hydroxy-5-O-rhamno-pyranoside (1) has been isolated from the ethanolic extract of seed pods of Bauhinia retusa. Its structure was established by extensive spectroscopic techniques (UV, IR, ID NMR, 2D NMR, HRESIMS).
2011, 22(9): 1084-1086
doi: 10.1016/j.cclet.2011.03.019
Abstract:
A novel method for the cation analysis was investigated. The analysis is based on the sparking of the salts of metals in a microwave oven after placing in a graphite cell. The graphite cell absorbs microwaves and produces high temperature which converts the salt into light emitting species. The colour of light was found to dependent on the nature of cation, however, the intensity of the emitted light was found to be depending upon the form and shape of the graphite assembly in addition to the concentration of the salt. This communication presents explanation for all these observations and for the systematic and quantitative analysis using microwave spark emission technique.
A novel method for the cation analysis was investigated. The analysis is based on the sparking of the salts of metals in a microwave oven after placing in a graphite cell. The graphite cell absorbs microwaves and produces high temperature which converts the salt into light emitting species. The colour of light was found to dependent on the nature of cation, however, the intensity of the emitted light was found to be depending upon the form and shape of the graphite assembly in addition to the concentration of the salt. This communication presents explanation for all these observations and for the systematic and quantitative analysis using microwave spark emission technique.
2011, 22(9): 1087-1090
doi: 10.1016/j.cclet.2011.03.008
Abstract:
A PVC membrane electrode based on copper (Ⅱ) bis (N-2-bromophenylsalicyldenaminato) as ionophor was prepared. The ion selective electrode was tested by inorganic anions and showed a good selectivity for iodide ion. This sensor exhibited Nernstian behavior with a slope of -57.8 mV per decade at 25℃. The proposed electrode showed a linear range from 1.0×10-5 to 1.0×10-1 mol/L with a detection limit of 5.0×10-6 mol/L. The electrode response was independent of pH in the range of 3.0-10.0. The proposed sensor was applied to determine the iodide in water and antiseptic samples.
A PVC membrane electrode based on copper (Ⅱ) bis (N-2-bromophenylsalicyldenaminato) as ionophor was prepared. The ion selective electrode was tested by inorganic anions and showed a good selectivity for iodide ion. This sensor exhibited Nernstian behavior with a slope of -57.8 mV per decade at 25℃. The proposed electrode showed a linear range from 1.0×10-5 to 1.0×10-1 mol/L with a detection limit of 5.0×10-6 mol/L. The electrode response was independent of pH in the range of 3.0-10.0. The proposed sensor was applied to determine the iodide in water and antiseptic samples.
2011, 22(9): 1091-1094
doi: 10.1016/j.cclet.2011.04.009
Abstract:
Magnetic anion exchange resin (MD-1) was prepared from quaternization of magnetic copolymeric resin (glycidyl methacry-late-co-divinylbenzene). For comparison, magnetic resin MD-0 without quaternization and non-magnetic resin (D-1) were also synthesized for the adsorption process. It was found that the adsorption was mainly contributed to the chemical interaction between quaternary ammonium groups and reactive blue RXHC. Due to the smaller size, MD-1 had faster adsorption and desorption kinetics than D-1. Coupled with the advantage of easy separation, the magnetic anion exchange resin was considered to be superior to common anion exchange resin in removal of reactive dye.
Magnetic anion exchange resin (MD-1) was prepared from quaternization of magnetic copolymeric resin (glycidyl methacry-late-co-divinylbenzene). For comparison, magnetic resin MD-0 without quaternization and non-magnetic resin (D-1) were also synthesized for the adsorption process. It was found that the adsorption was mainly contributed to the chemical interaction between quaternary ammonium groups and reactive blue RXHC. Due to the smaller size, MD-1 had faster adsorption and desorption kinetics than D-1. Coupled with the advantage of easy separation, the magnetic anion exchange resin was considered to be superior to common anion exchange resin in removal of reactive dye.
2011, 22(9): 1095-1098
doi: 10.1016/j.cclet.2011.03.020
Abstract:
A novel kind of supported combined liquid membrane (SCLM) has been studied for the Gd (Ⅲ) transfer. SCLM contained polyvinylidene fluoride membrane (PVDF) as the liquid membrane support and renewal solution including HNO3 solution as the stripping solution and 2-ethyl hexyl phosphonic acid-mono-2-ethyl hexyl ester (HEH (EH)P) as the carrier dissolved in kerosene. The mixed solution of carrier and kerosene was membrane solution. The optimum transport conditions of Gd (Ⅲ) were that concentration of HNO3 solution was 4.00 mol/L, concentration of carrier was 0.16 mol/L, and volume ratio of membrane solution to stripping solution was 30:30 of the renewal phase, and pH value was 4.80 of the feed phase. Under the optimum condition studied, when initial concentration of Gd (Ⅲ) was 1.00×10-4 mol/L, the transfer rate of Gd (Ⅲ) was 96.8% during 130 min.
A novel kind of supported combined liquid membrane (SCLM) has been studied for the Gd (Ⅲ) transfer. SCLM contained polyvinylidene fluoride membrane (PVDF) as the liquid membrane support and renewal solution including HNO3 solution as the stripping solution and 2-ethyl hexyl phosphonic acid-mono-2-ethyl hexyl ester (HEH (EH)P) as the carrier dissolved in kerosene. The mixed solution of carrier and kerosene was membrane solution. The optimum transport conditions of Gd (Ⅲ) were that concentration of HNO3 solution was 4.00 mol/L, concentration of carrier was 0.16 mol/L, and volume ratio of membrane solution to stripping solution was 30:30 of the renewal phase, and pH value was 4.80 of the feed phase. Under the optimum condition studied, when initial concentration of Gd (Ⅲ) was 1.00×10-4 mol/L, the transfer rate of Gd (Ⅲ) was 96.8% during 130 min.
2011, 22(9): 1099-1102
doi: 10.1016/j.cclet.2011.01.041
Abstract:
Spherical Ni0.8Co0.15Al0.05OOH precursor, prepared by a co-oxidation-controlled crystallization method, was used to synthesize LiNi0.8Co0.15Al0.05O2. The obtained LiNi0.8Co0.15Al0.05O2 materials showed excellent electrochemical performance, with an initial discharge capacity of 193.5 mAh/g and capacity retention of 95.1% after 50 cycles when cycled at 0.2 C rate between 2.8 and 4.3 V.
Spherical Ni0.8Co0.15Al0.05OOH precursor, prepared by a co-oxidation-controlled crystallization method, was used to synthesize LiNi0.8Co0.15Al0.05O2. The obtained LiNi0.8Co0.15Al0.05O2 materials showed excellent electrochemical performance, with an initial discharge capacity of 193.5 mAh/g and capacity retention of 95.1% after 50 cycles when cycled at 0.2 C rate between 2.8 and 4.3 V.
2011, 22(9): 1103-1106
doi: 10.1016/j.cclet.2011.04.006
Abstract:
A zeolite composite composed of ZSM-5 and β-zeolites has been synthesized by a procedure of the nucleation and crystallization of ZSM-5 zeolite in the hollow β-zeolite. The property of β-zeolite crystals with aluminum-poor interior and aluminum-rich outer rim results in silicon extraction favorably in the aluminum-poor bulk rather than the aluminum-rich external surface. Subsequently, alkaline treatment of β-zeolite crystals during the second-step synthesis leads to a preferential dissolution of the aluminum-poor center and the formation of hollow β-zeolite crystals. ZSM-5 zeolite crystals are therefore embedded and grown within the hollow β-zeolite. The catalytic activities of Co-Hβ, Co-HZSM-5 and Co-HZSM-5/BEA are investigated during the reaction of methane catalytic reduction NO in the presence of O2.
A zeolite composite composed of ZSM-5 and β-zeolites has been synthesized by a procedure of the nucleation and crystallization of ZSM-5 zeolite in the hollow β-zeolite. The property of β-zeolite crystals with aluminum-poor interior and aluminum-rich outer rim results in silicon extraction favorably in the aluminum-poor bulk rather than the aluminum-rich external surface. Subsequently, alkaline treatment of β-zeolite crystals during the second-step synthesis leads to a preferential dissolution of the aluminum-poor center and the formation of hollow β-zeolite crystals. ZSM-5 zeolite crystals are therefore embedded and grown within the hollow β-zeolite. The catalytic activities of Co-Hβ, Co-HZSM-5 and Co-HZSM-5/BEA are investigated during the reaction of methane catalytic reduction NO in the presence of O2.
2011, 22(9): 1107-1110
doi: 10.1016/j.cclet.2011.03.018
Abstract:
Terephthaloyl chloride (DB)-modified silk fibroin (SF) films were immersed into 1.5 times simulated body fluid (1.5 SBF) to regulate the mineralization of hydroxyapatite (HA) crystals at about 36.5℃ for 24 h. UV was used to prove that the new bonds form between the DB and SF. The structure and morphology of the SF/HA were investigated by FTIR, ICP, XRD and SEM. The results showed that the apatite deposited on the matrix of SF mainly was HA. HA was self-assembled on the matrix of SF and formed three-dimensional framework when the weight ratio of DB/SF was 0.30. The content of DB affected the structure and morphology of the apatite composites deposited on the SF films.
Terephthaloyl chloride (DB)-modified silk fibroin (SF) films were immersed into 1.5 times simulated body fluid (1.5 SBF) to regulate the mineralization of hydroxyapatite (HA) crystals at about 36.5℃ for 24 h. UV was used to prove that the new bonds form between the DB and SF. The structure and morphology of the SF/HA were investigated by FTIR, ICP, XRD and SEM. The results showed that the apatite deposited on the matrix of SF mainly was HA. HA was self-assembled on the matrix of SF and formed three-dimensional framework when the weight ratio of DB/SF was 0.30. The content of DB affected the structure and morphology of the apatite composites deposited on the SF films.
2011, 22(9): 1111-1114
doi: 10.1016/j.cclet.2011.04.008
Abstract:
Two homologous series of bent-shaped molecules composed of low bent-angle naphthalene central core and long alkoxy tail or alkylthio tail, N (1, 7)-n-OPIMB and N (1, 7)-n-SPIMB (n=20, 22), respectively, were synthesized. The mesomorphic properties were investigated by differential scanning calorimetry (DSC), polarizing optical microscopy (POM) and X-ray diffraction (XRD). Compared to the direct transition from the isotropic phase to the chiral B4 phase examined in N (1, 7)-n-OPIMB, N (1, 7)-n-SPIMB exhibited a rare Iso-Ncol-Colh-B4 phase sequence. The combination of the asymmetric low bent-angle 1, 7-naphathalene central core and the flexible long alkylthio tail is considered to play an important role in the formation of such a novel phase sequence.
Two homologous series of bent-shaped molecules composed of low bent-angle naphthalene central core and long alkoxy tail or alkylthio tail, N (1, 7)-n-OPIMB and N (1, 7)-n-SPIMB (n=20, 22), respectively, were synthesized. The mesomorphic properties were investigated by differential scanning calorimetry (DSC), polarizing optical microscopy (POM) and X-ray diffraction (XRD). Compared to the direct transition from the isotropic phase to the chiral B4 phase examined in N (1, 7)-n-OPIMB, N (1, 7)-n-SPIMB exhibited a rare Iso-Ncol-Colh-B4 phase sequence. The combination of the asymmetric low bent-angle 1, 7-naphathalene central core and the flexible long alkylthio tail is considered to play an important role in the formation of such a novel phase sequence.
2011, 22(9): 1115-1118
doi: 10.1016/j.cclet.2011.03.011
Abstract:
A combination of photochlorination of p-xylene and succedent Friedel-Crafts alkylation polymerization was firstly used in the preparation of the hypercrosslinked adsorptive resin. The data of GC-MS and GC showed that a series of chlorizates were produced when p-xylene was photochlorinated. Hypercrosslinked resins could be synthesized by copolymerization, self-polymerization of chlorizates or post crosslinking reaction. The chemical structure and micromorphology of the porous resins were characterized by BET, FT-IR, SEM and elementary analysis (EA). The results showed that the novel adsorptive resins possess high BET surface near to 1038 m2/g and large pore volumes range from 0.5 to 1.2 cm3/g.
A combination of photochlorination of p-xylene and succedent Friedel-Crafts alkylation polymerization was firstly used in the preparation of the hypercrosslinked adsorptive resin. The data of GC-MS and GC showed that a series of chlorizates were produced when p-xylene was photochlorinated. Hypercrosslinked resins could be synthesized by copolymerization, self-polymerization of chlorizates or post crosslinking reaction. The chemical structure and micromorphology of the porous resins were characterized by BET, FT-IR, SEM and elementary analysis (EA). The results showed that the novel adsorptive resins possess high BET surface near to 1038 m2/g and large pore volumes range from 0.5 to 1.2 cm3/g.
2011, 22(9): 1119-1122
doi: 10.1016/j.cclet.2011.04.003
Abstract:
Amphiphilic fluorosiloxane graft copolymers with a poly (dimethylsiloxane) (PDMS) backbone, a hydrophobic fluorosiloxane side-chain and three hydrophilic polyether side-chains were synthesized by hydrosilation reaction in this work. The micellization of amphiphilic graft copolymers in the water/ethanol solvent system was investigated, and vesicles with different size were formed after the self-assembly system was aged for different time.
Amphiphilic fluorosiloxane graft copolymers with a poly (dimethylsiloxane) (PDMS) backbone, a hydrophobic fluorosiloxane side-chain and three hydrophilic polyether side-chains were synthesized by hydrosilation reaction in this work. The micellization of amphiphilic graft copolymers in the water/ethanol solvent system was investigated, and vesicles with different size were formed after the self-assembly system was aged for different time.
2011, 22(9): 1123-1126
doi: 10.1016/j.cclet.2011.04.005
Abstract:
Three model drugs with different function groups were chosen to dialyze with dextran-graft-poly (N-isopropylacrylamide). Only ibuprofen could induce the formation of drug loaded micelles, which was confirmed with dynamic light scattering and transmission electron microscope. Hydrogen-bonding between the amide groups of poly (N-isopropylacrylamide) and the carboxyl groups of ibuprofen was driving force for the drug-loaded micelle. It was also found that the diameter of the ibuprofen-loaded micelles changed reversibly against temperature.
Three model drugs with different function groups were chosen to dialyze with dextran-graft-poly (N-isopropylacrylamide). Only ibuprofen could induce the formation of drug loaded micelles, which was confirmed with dynamic light scattering and transmission electron microscope. Hydrogen-bonding between the amide groups of poly (N-isopropylacrylamide) and the carboxyl groups of ibuprofen was driving force for the drug-loaded micelle. It was also found that the diameter of the ibuprofen-loaded micelles changed reversibly against temperature.
2011, 22(9): 1127-1129
doi: 10.1016/j.cclet.2011.04.018
Abstract:
Submicron-sized peanut-shaped poly (methyl methacrylate)/polystyrene (PMMA/PS) particles were successfully synthesized by seeded soap-free emulsion polymerization of styrene on the spherical crosslinked PMMA seed particles. The obtained peanut-shaped particles showed a novel internal morphology:PS phase formed one domain which linked to the other domain having PMMA core encased by PS shell.
Submicron-sized peanut-shaped poly (methyl methacrylate)/polystyrene (PMMA/PS) particles were successfully synthesized by seeded soap-free emulsion polymerization of styrene on the spherical crosslinked PMMA seed particles. The obtained peanut-shaped particles showed a novel internal morphology:PS phase formed one domain which linked to the other domain having PMMA core encased by PS shell.
2011, 22(9): 1130-1134
doi: 10.1016/j.cclet.2011.05.001
Abstract:
A ligand is a small molecule bind to several residues of a receptor. We adapt the concept of molecular path for effective ligand search with its contacting residues. Additionally, we allow wild type definitions on atoms and bonds of molecular paths for fuzzy algorithms on structural match. We choose hydrogen bond interactions to characterize the binding mode of a ligand by several proper molecular paths and use them to query the deposited ligands in PDBe that interact with their residues in the same way. Expression of molecular path and format of database entries are described with examples. Our molecular path provides a new approach to explore the ligand-receptor interactions and to provide structural framework reference on new ligand design.
A ligand is a small molecule bind to several residues of a receptor. We adapt the concept of molecular path for effective ligand search with its contacting residues. Additionally, we allow wild type definitions on atoms and bonds of molecular paths for fuzzy algorithms on structural match. We choose hydrogen bond interactions to characterize the binding mode of a ligand by several proper molecular paths and use them to query the deposited ligands in PDBe that interact with their residues in the same way. Expression of molecular path and format of database entries are described with examples. Our molecular path provides a new approach to explore the ligand-receptor interactions and to provide structural framework reference on new ligand design.
