An efficient, practical, highly selective and environmentally benign method is reported for the synthesis of aryl thioethers via the coupling of thiols with aryl boronic acids in the presence of NaOH and a catalytic a...An efficient, practical, highly selective and environmentally benign method is reported for the synthesis of aryl thioethers via the coupling of thiols with aryl boronic acids in the presence of NaOH and a catalytic amount of CuSO4 at 130 ℃ using water as a green solvent. The products were obtained in moderate to excellent yields;more importantly, the use of toxic ligands and solvents was avoided. A broad range of aryl boronic acids and scalable processes make this methodology valuable and versatile for the synthesis of a broad range of aryl sulfides.展开更多
In this paper the hydrogen and hydrocarbon gas sensing performance of the Pt/Catalysed TiO_2/SiC devices have been studied.The TiO_2 metal oxide thin films were catalytically modified employing Pt and Pd.The electrica...In this paper the hydrogen and hydrocarbon gas sensing performance of the Pt/Catalysed TiO_2/SiC devices have been studied.The TiO_2 metal oxide thin films were catalytically modified employing Pt and Pd.The electrical properties of the fabricated devices were studied by measuring their capacitance-voltage (C-V),conductance-voltage (G-V) and dynamic response characteristics.The sensor's response as a function of operating temperature (25℃to 700℃) and concentrations less than 1% of the analyte gases have been investigated.The sensitivity of the Pt catalysed TiO_2 sensor was found to be superior when compared to TiO_2 catalysed with Pd.A voltage shift of 3.2 V for 1% propene at 420℃and 2.8 V for 1% hydrogen at 250℃in an ambient containing synthetic air was recorded for the Pt catalysed TiO_2 sensor.The response of Pt catalysed TiO_2 sensor was found to be approximately 4 times larger when compared to the non catalysed counterpart.展开更多
The ~3H-labelled belladonna alkaloids obtained by catalysed exchange method with microwave excitation was investigated. The specific activities of the labelled products Were 16—32 TBq/mol. More than 90% labelled posi...The ~3H-labelled belladonna alkaloids obtained by catalysed exchange method with microwave excitation was investigated. The specific activities of the labelled products Were 16—32 TBq/mol. More than 90% labelled positions of these ~3H-tracers were on phenyl rings. The radiochemical purity and chemical purity of crude products were both in 75—80%.展开更多
Aniline was polymerized in dilute aqueous squaric acid and the polyaniline(PAn) was doped with 10 -1 10 -3 mol/L of squaric acid. The corresponding electrical conductivity of the PAn is 10 -1 ...Aniline was polymerized in dilute aqueous squaric acid and the polyaniline(PAn) was doped with 10 -1 10 -3 mol/L of squaric acid. The corresponding electrical conductivity of the PAn is 10 -1 10 -2 S·cm -1 . The solubility of the doped PAn has been improved in common polar organic solvents . The FTIR and UV-Vis spectra show that the PAn has the structure of both quinone and imine .展开更多
We report a general and highly efficient Mukaiyama-aldol reaction of ketones and difluoroenoxysilanes.While the reaction of aryl ketones worked efficiently in the presence of Bi(OTf)_3, that of aliphatic ketones requi...We report a general and highly efficient Mukaiyama-aldol reaction of ketones and difluoroenoxysilanes.While the reaction of aryl ketones worked efficiently in the presence of Bi(OTf)_3, that of aliphatic ketones required the use of Sc(OTf_)3. In addition, Sc(OTf)_3 was capable of achieving excellent 1,2-selectivity in the corresponding reaction of α,β-unsaturated ketones. This method provides a facile access to differently substituted β-hydroxy α,α-difluoro ketones, versatile synthons for difluomethylated tertiary alcohols.展开更多
The electrochemical reduction of carbon dioxide(CO_(2))into value-added chemicals and fuels has been extensively studied as a promising strategy for mitigating environmental issues and achieving sustainable energy con...The electrochemical reduction of carbon dioxide(CO_(2))into value-added chemicals and fuels has been extensively studied as a promising strategy for mitigating environmental issues and achieving sustainable energy conversion.Substantial efforts have been made to improve the understanding of CO_(2)reduction reaction(CO_(2)RR)mechanisms by computational and spectroscopic studies.An in-depth understanding of CO_(2)RR mechanism can provide the guidance and criteria for designing high-efficiency catalysts,and hence,steering CO_(2)RR to desired products.This review systematically discusses the formation mechanisms and reaction pathways of various CO_(2)RR products,including C_(1)products(CO,HCOOH,and CH_(4)),C_(2)products(C_(2)H_(4),C_(2)H_(5)OH,and CH_(3)COOH),and C_(3+)products(C_(3)H_(6),C_(3)H_(7)OH,and others).The reaction pathways are elucidated by analyzing the adsorption behavior,energy barriers,and intermediate coupling steps involved in the generation of each product.Particular emphasis is placed on the key intermediates,such as^(*)OCHO,^(*)COOH,^(*)CO,^(*)OCCOH,and^(*)CCO,which play crucial roles in determining the product selectivity.The effects of catalyst composition,morphology,and electronic structure on the adsorption and activation of these intermediates are also discussed.Moreover,advanced characterization techniques,including in-situ spectroscopy and isotopic labeling experiments,are highlighted for their contributions to unraveling the reaction mechanisms.The review aims to provide critical insights to reveal the activity-determining para meters and underlying CO_(2)RR mechanisms,which will guide the rational design of next-generation electrocatalysts for selective CO^(2)RR towards high-value products.展开更多
Poly（N-vinyl-2-pyrrolidone）-protected Pt/Au bimetallic nanoparticles were obtained by reducing the mixture of HAuCl4 and H2PtCl6 with sodium borohydride.UV-vis spectra,transmission electronic microscopy and X-ray di...Poly（N-vinyl-2-pyrrolidone）-protected Pt/Au bimetallic nanoparticles were obtained by reducing the mixture of HAuCl4 and H2PtCl6 with sodium borohydride.UV-vis spectra,transmission electronic microscopy and X-ray diffraction reveal that the prepared bimetallic nanoparticles are of alloy structure.展开更多
基金Funded by the National Natural Science Foundation of China(No.21571144)
文摘An efficient, practical, highly selective and environmentally benign method is reported for the synthesis of aryl thioethers via the coupling of thiols with aryl boronic acids in the presence of NaOH and a catalytic amount of CuSO4 at 130 ℃ using water as a green solvent. The products were obtained in moderate to excellent yields;more importantly, the use of toxic ligands and solvents was avoided. A broad range of aryl boronic acids and scalable processes make this methodology valuable and versatile for the synthesis of a broad range of aryl sulfides.
文摘In this paper the hydrogen and hydrocarbon gas sensing performance of the Pt/Catalysed TiO_2/SiC devices have been studied.The TiO_2 metal oxide thin films were catalytically modified employing Pt and Pd.The electrical properties of the fabricated devices were studied by measuring their capacitance-voltage (C-V),conductance-voltage (G-V) and dynamic response characteristics.The sensor's response as a function of operating temperature (25℃to 700℃) and concentrations less than 1% of the analyte gases have been investigated.The sensitivity of the Pt catalysed TiO_2 sensor was found to be superior when compared to TiO_2 catalysed with Pd.A voltage shift of 3.2 V for 1% propene at 420℃and 2.8 V for 1% hydrogen at 250℃in an ambient containing synthetic air was recorded for the Pt catalysed TiO_2 sensor.The response of Pt catalysed TiO_2 sensor was found to be approximately 4 times larger when compared to the non catalysed counterpart.
基金The Project Supported by National Natural Science Foundation of China
文摘The ~3H-labelled belladonna alkaloids obtained by catalysed exchange method with microwave excitation was investigated. The specific activities of the labelled products Were 16—32 TBq/mol. More than 90% labelled positions of these ~3H-tracers were on phenyl rings. The radiochemical purity and chemical purity of crude products were both in 75—80%.
文摘Aniline was polymerized in dilute aqueous squaric acid and the polyaniline(PAn) was doped with 10 -1 10 -3 mol/L of squaric acid. The corresponding electrical conductivity of the PAn is 10 -1 10 -2 S·cm -1 . The solubility of the doped PAn has been improved in common polar organic solvents . The FTIR and UV-Vis spectra show that the PAn has the structure of both quinone and imine .
基金supported by the National Basic Research Program of China (2015CB856600)the National Natural Science Foundation of China (21472049)
文摘We report a general and highly efficient Mukaiyama-aldol reaction of ketones and difluoroenoxysilanes.While the reaction of aryl ketones worked efficiently in the presence of Bi(OTf)_3, that of aliphatic ketones required the use of Sc(OTf_)3. In addition, Sc(OTf)_3 was capable of achieving excellent 1,2-selectivity in the corresponding reaction of α,β-unsaturated ketones. This method provides a facile access to differently substituted β-hydroxy α,α-difluoro ketones, versatile synthons for difluomethylated tertiary alcohols.
基金financially supported by the National Natural Science Foundation of China(Grants 22225901,21975237 and 51702312)the Fundamental Research Funds for the Central Universities(Grant WK2340000101)+5 种基金the USTC Research Funds of the Double First-Class Initiative(Grant YD2340002007 and YD9990002017)the Open Funds of the State Key Laboratory of Rare Earth Resource Utilization(Grant RERU2022007)the China Postdoctoral Science Foundation(Grants 2023M733371,2024M750006 and 2023T160617)Postdoctoral Fellowship Program(Grade C)of China Postdoctoral Science Foundation(GZC20230008)the Natural Science Foundation Youth Project of Anhui Province(2408085QB065)the Postdoctoral Research Funding Project of Anhui Province(2023B727)。
文摘The electrochemical reduction of carbon dioxide(CO_(2))into value-added chemicals and fuels has been extensively studied as a promising strategy for mitigating environmental issues and achieving sustainable energy conversion.Substantial efforts have been made to improve the understanding of CO_(2)reduction reaction(CO_(2)RR)mechanisms by computational and spectroscopic studies.An in-depth understanding of CO_(2)RR mechanism can provide the guidance and criteria for designing high-efficiency catalysts,and hence,steering CO_(2)RR to desired products.This review systematically discusses the formation mechanisms and reaction pathways of various CO_(2)RR products,including C_(1)products(CO,HCOOH,and CH_(4)),C_(2)products(C_(2)H_(4),C_(2)H_(5)OH,and CH_(3)COOH),and C_(3+)products(C_(3)H_(6),C_(3)H_(7)OH,and others).The reaction pathways are elucidated by analyzing the adsorption behavior,energy barriers,and intermediate coupling steps involved in the generation of each product.Particular emphasis is placed on the key intermediates,such as^(*)OCHO,^(*)COOH,^(*)CO,^(*)OCCOH,and^(*)CCO,which play crucial roles in determining the product selectivity.The effects of catalyst composition,morphology,and electronic structure on the adsorption and activation of these intermediates are also discussed.Moreover,advanced characterization techniques,including in-situ spectroscopy and isotopic labeling experiments,are highlighted for their contributions to unraveling the reaction mechanisms.The review aims to provide critical insights to reveal the activity-determining para meters and underlying CO_(2)RR mechanisms,which will guide the rational design of next-generation electrocatalysts for selective CO^(2)RR towards high-value products.
文摘Poly（N-vinyl-2-pyrrolidone）-protected Pt/Au bimetallic nanoparticles were obtained by reducing the mixture of HAuCl4 and H2PtCl6 with sodium borohydride.UV-vis spectra,transmission electronic microscopy and X-ray diffraction reveal that the prepared bimetallic nanoparticles are of alloy structure.
