This work presents a new greener alternative for biocondensation of aldehydes and indoles for the synthesis of bis- and tris(indolyl)methanes catalyzed by lemon juice (Citrus limon) in good yields under ultrasound irr...This work presents a new greener alternative for biocondensation of aldehydes and indoles for the synthesis of bis- and tris(indolyl)methanes catalyzed by lemon juice (Citrus limon) in good yields under ultrasound irradiation in aqueous ethanol. Various substituted aldehydes with indoles under this reaction condition are elucidated. Also, tetraindolyl compounds were prepared using terephthaldialdehyde by following the same protocol. This method is an environmentally benign, efficient reaction, which requires shorter reaction time and simple experimental and work-up procedures.展开更多
A novel solid state cathodoluminescence(SSCL) device(the device has a structure of ITO/SiO2/Alq3/SiO2/Al) is fabricated using organic materials as the fluorescent film sandwiched between two SiO2 layers.When alternati...A novel solid state cathodoluminescence(SSCL) device(the device has a structure of ITO/SiO2/Alq3/SiO2/Al) is fabricated using organic materials as the fluorescent film sandwiched between two SiO2 layers.When alternating current(AC) voltage is applied to this device,uniform emissions are observed.When the voltage is 50 V,a longer wavelength emission(522 nm) is obtained,but the shorter wavelength emission(465 nm) is dominant when the voltage is 76 V.The origins of these emissions are discussed.The interface formed between SiO2 and tris-(8-hydroquinoline) aluminum(Alq3) of SSCL device was investigated by using X-ray photoelectron spectroscopy(XPS).Analyses of the XPS spectra reveal a deep diffusion of the indium into the interface.On the other hand,the interaction between indium and Alq3 occurs at the interface and results in the formation of a carbon-oxygen-metal(In or Al) complex in the contact region.This effect causes a luminescence quenching in the SSCL device.展开更多
A series of novel chiral tetrahedral heterometal clusters have firstly been separated on cellulose tris-(3,5-dimethylphenylcarbamate) stationary phase by high performance liquid chrom-atography, using hexane as the mo...A series of novel chiral tetrahedral heterometal clusters have firstly been separated on cellulose tris-(3,5-dimethylphenylcarbamate) stationary phase by high performance liquid chrom-atography, using hexane as the mobile phase with various alcohols as modifiers.展开更多
Objective To investigate the electrochemiluminescence (ECL) behavior of cloperastine hydrochloride. Methods ECL intensity of tris (2,2′-bipyridyl) rutheniumo(Ⅱ) was enhanced, the method for the determination of clop...Objective To investigate the electrochemiluminescence (ECL) behavior of cloperastine hydrochloride. Methods ECL intensity of tris (2,2′-bipyridyl) rutheniumo(Ⅱ) was enhanced, the method for the determination of cloperastine hydrochloride was established using capillary electrophoresis (CE) coupled with electrochemilumolinescence (ECL) detection. Results Under the optimum conditions, ECL intensity varied linearly with cloperastine hydrochloride concentration from 7.0×10-6g/mL to 1.0×10-4g/mL. The detection limit (S/N=3) was 8.05×10-7g/mL. The relative standard deviation of the ECL intensity and the migration time for 11 consecutive injections of 1.0×10-5g/mL cloperastine hydrochloride was 2.9% and 1.5%, respectively. This method was successfully applied to cloperastine hydrochloride tablet determination. Conclusion The method has been established, validated and applied for determination of cloperastine hydrochloride.展开更多
It was observed that hydrazine could enhance the chemiluminescence （CL） intensity of tris-（1,10 phenanthroline）ruthenium（Ⅱ） （Ru（ phen）3^2＋ ）- Cerium（ Ⅳ ） ice（ Ⅳ ）） system, based on which, a novel CL...It was observed that hydrazine could enhance the chemiluminescence （CL） intensity of tris-（1,10 phenanthroline）ruthenium（Ⅱ） （Ru（ phen）3^2＋ ）- Cerium（ Ⅳ ） ice（ Ⅳ ）） system, based on which, a novel CL system, Ru（phen）3^2＋ Hydrazine-Ce（Ⅳ）, was established. This CL system was investigated and employed to detect hydrazine. Under the optimum experimental conditions, the linear range and detection limit of the proposed method are 2.0× 10^-6-2.0×10^-3g·L^-1 and 1. 8×10^-6g·L^-1, respectively. For 1. 5 × 10^-5, 1.5×10^-4 and 1.2×10^-3 g·L^-1 hydrazine, the relative standard deviation （RSD） is 2.9%, 2.2% and 3. 1%, respectively （n= 11）. The proposed method has been used to detect the content of hydrazine in the synthetic samples with satisfactory results.展开更多
Dipeptides are stereo-specifically involved in several biological functions that are challenging to separate enantiomerically. Elution order of enantiomers is an important issue in chiral chromatography. Amylose tris-...Dipeptides are stereo-specifically involved in several biological functions that are challenging to separate enantiomerically. Elution order of enantiomers is an important issue in chiral chromatography. Amylose tris-(3,5-dimethylphenylcarbamate) chiral stationary phase(CSP) is the best and most-widely-used CSP in chiral separations, but experimental data of enantiomeric separation of dipeptides on this CSP is lacking. Simulation studies were conducted to determine the order of elution and the chiral recognition mechanism of didpetides on this CSP. Results indicated that the docking energy of SR-enantiomers were higher than SS-antipodes. The range of docking energies for SR-enantiomers was -7.44 to -5.92 kcal/mol with CSP, but -7.15 to -5.87 kcal/mol for SS-stereoisomers. Therefore it is predicted that SS-enantiomer will elute first, followed by SR-antipode. Furthermore, hydrogen bondings, van der Waal's interactions and electrostatic interactions were observed among SR- and SSenantiomers and chiral grooves of CSP. The number of hydrogen bonds was one in each enantiomer binding except S-Ala-R-Tyr, which contained two hydrogen bonds. No hydrogen bond was found in S-Ala-R-Trp, S-Leu-S-Trp, and S-Leu-S-Tyr dipeptides bindings. The chiral recognition mechanisms dictate different strengths of stereoselective bindings of the enantiomers on CSP.展开更多
文摘This work presents a new greener alternative for biocondensation of aldehydes and indoles for the synthesis of bis- and tris(indolyl)methanes catalyzed by lemon juice (Citrus limon) in good yields under ultrasound irradiation in aqueous ethanol. Various substituted aldehydes with indoles under this reaction condition are elucidated. Also, tetraindolyl compounds were prepared using terephthaldialdehyde by following the same protocol. This method is an environmentally benign, efficient reaction, which requires shorter reaction time and simple experimental and work-up procedures.
基金supported by the National Natural Science Foundation of China (Grant No. 60806047)the Natural Science Foundation Project of CQ CSTC (Grant No. 2009BB2237)+1 种基金the Science and Technology of Chongqing Municipal Education Commission (Grant No. KJ080816)the Natural Science Foundation of Chongqing Normal University (Grant Nos. 07XLB015 and 08XLS12)
文摘A novel solid state cathodoluminescence(SSCL) device(the device has a structure of ITO/SiO2/Alq3/SiO2/Al) is fabricated using organic materials as the fluorescent film sandwiched between two SiO2 layers.When alternating current(AC) voltage is applied to this device,uniform emissions are observed.When the voltage is 50 V,a longer wavelength emission(522 nm) is obtained,but the shorter wavelength emission(465 nm) is dominant when the voltage is 76 V.The origins of these emissions are discussed.The interface formed between SiO2 and tris-(8-hydroquinoline) aluminum(Alq3) of SSCL device was investigated by using X-ray photoelectron spectroscopy(XPS).Analyses of the XPS spectra reveal a deep diffusion of the indium into the interface.On the other hand,the interaction between indium and Alq3 occurs at the interface and results in the formation of a carbon-oxygen-metal(In or Al) complex in the contact region.This effect causes a luminescence quenching in the SSCL device.
基金supported by the Chinese Academy of Sciences under a‘Hundreds of Talents program’to Yonmnin Li.
文摘A series of novel chiral tetrahedral heterometal clusters have firstly been separated on cellulose tris-(3,5-dimethylphenylcarbamate) stationary phase by high performance liquid chrom-atography, using hexane as the mobile phase with various alcohols as modifiers.
文摘Objective To investigate the electrochemiluminescence (ECL) behavior of cloperastine hydrochloride. Methods ECL intensity of tris (2,2′-bipyridyl) rutheniumo(Ⅱ) was enhanced, the method for the determination of cloperastine hydrochloride was established using capillary electrophoresis (CE) coupled with electrochemilumolinescence (ECL) detection. Results Under the optimum conditions, ECL intensity varied linearly with cloperastine hydrochloride concentration from 7.0×10-6g/mL to 1.0×10-4g/mL. The detection limit (S/N=3) was 8.05×10-7g/mL. The relative standard deviation of the ECL intensity and the migration time for 11 consecutive injections of 1.0×10-5g/mL cloperastine hydrochloride was 2.9% and 1.5%, respectively. This method was successfully applied to cloperastine hydrochloride tablet determination. Conclusion The method has been established, validated and applied for determination of cloperastine hydrochloride.
基金Supported by Alexander von Humboldt Founda-tion,the National Natural Science Foundation of China (20575046) National Key Basic Research and Development Program (973 Pro-gram,2002CB211800) .
文摘It was observed that hydrazine could enhance the chemiluminescence （CL） intensity of tris-（1,10 phenanthroline）ruthenium（Ⅱ） （Ru（ phen）3^2＋ ）- Cerium（ Ⅳ ） ice（ Ⅳ ）） system, based on which, a novel CL system, Ru（phen）3^2＋ Hydrazine-Ce（Ⅳ）, was established. This CL system was investigated and employed to detect hydrazine. Under the optimum experimental conditions, the linear range and detection limit of the proposed method are 2.0× 10^-6-2.0×10^-3g·L^-1 and 1. 8×10^-6g·L^-1, respectively. For 1. 5 × 10^-5, 1.5×10^-4 and 1.2×10^-3 g·L^-1 hydrazine, the relative standard deviation （RSD） is 2.9%, 2.2% and 3. 1%, respectively （n= 11）. The proposed method has been used to detect the content of hydrazine in the synthetic samples with satisfactory results.
基金the Department of Science and Technology, New Delhi, India (DST/INT/RFBR/P-147)the Russian Foundation of Basic Research, Russia (RFBR 13-03-92692) for financial assistance
文摘Dipeptides are stereo-specifically involved in several biological functions that are challenging to separate enantiomerically. Elution order of enantiomers is an important issue in chiral chromatography. Amylose tris-(3,5-dimethylphenylcarbamate) chiral stationary phase(CSP) is the best and most-widely-used CSP in chiral separations, but experimental data of enantiomeric separation of dipeptides on this CSP is lacking. Simulation studies were conducted to determine the order of elution and the chiral recognition mechanism of didpetides on this CSP. Results indicated that the docking energy of SR-enantiomers were higher than SS-antipodes. The range of docking energies for SR-enantiomers was -7.44 to -5.92 kcal/mol with CSP, but -7.15 to -5.87 kcal/mol for SS-stereoisomers. Therefore it is predicted that SS-enantiomer will elute first, followed by SR-antipode. Furthermore, hydrogen bondings, van der Waal's interactions and electrostatic interactions were observed among SR- and SSenantiomers and chiral grooves of CSP. The number of hydrogen bonds was one in each enantiomer binding except S-Ala-R-Tyr, which contained two hydrogen bonds. No hydrogen bond was found in S-Ala-R-Trp, S-Leu-S-Trp, and S-Leu-S-Tyr dipeptides bindings. The chiral recognition mechanisms dictate different strengths of stereoselective bindings of the enantiomers on CSP.
