The dehydrogenation reaction of H2S by the ^3Σ^- ground state of VS^+: VS^+ + H2S → VS2^+ + H2 has been studied by using Density Functional Theory (DPT) at the B3LYP/DZVP level. It is found that the reaction...The dehydrogenation reaction of H2S by the ^3Σ^- ground state of VS^+: VS^+ + H2S → VS2^+ + H2 has been studied by using Density Functional Theory (DPT) at the B3LYP/DZVP level. It is found that the reaction proceeds along two possible pathways (A and B) yielding two isomer dehydrogenation products VS2^+-1 (^3B2) and VS2^+-2 (^3A1), respectively. For both pathways, the reaction has a two-step-reaction mechanism that involves the migration of two hydrogen atoms from S2 to V^+, respectively. The migration of the second hydrogen via TS3 and that of the first via TS4 are the rate-determining steps for pathways A and B, respectively. The activation energy is 17.4 kcal/mol for pathway A and 22.8 kcal/mol for pathway B relative to the reactants. The calculated reaction heat of 9.9 kcal/mol indicates the endothermicity of pathway A and that of -11.9 kcal/mol suggests the exothermicity of pathway B.展开更多
Metalation reac-tion of metal-free phthalocyanine molecule with Co atom adsorbed on Au(111)surface has been studied in situ at single atom/molecule scale by low-temperature scanning tunneling microscopy(STM)experiment...Metalation reac-tion of metal-free phthalocyanine molecule with Co atom adsorbed on Au(111)surface has been studied in situ at single atom/molecule scale by low-temperature scanning tunneling microscopy(STM)experiment combined with simulations based on density function theory calculations.Through manipulations using STM tip,we showed a controlled manner to have a single metal-free phthalocyanine molecule react with a Co atom to form Co phthalocyanine molecule.In this reaction process,an intermediate state originating from π-d interaction between the metal-free phthalocyanine molecule and Co atom has been identi ed.Moreover,we also revealed that the redox reaction represented as bond breaking and bond forming relative to the Co and pyrrolic N atoms,not pyrrolic H atoms,is a key process for dehydrogenation and metalation reaction.Our DFT calculations provided theoretical supporting for the above conclusions,and further understanding of the related mechanisms.展开更多
The kinetics and the mechanism of the formation reactions of M(PnAO)^(2+)(M=Ni,Co,Cu)were studied with UV Spectrophotometer and Stopped Flow Spectrophotometer and a three steps mechanism was suggested.
The transmetallation reaction of 4 Schiff base type arylmercury compounds with metallic tin has been carried out in refluxing xylene.It was found that the reaction proceeds in the same manner as that of chloro[2-(phen...The transmetallation reaction of 4 Schiff base type arylmercury compounds with metallic tin has been carried out in refluxing xylene.It was found that the reaction proceeds in the same manner as that of chloro[2-(phenylazo)phenyl]mercury(Ⅱ) to give dichlorobisaryltin(Ⅳ).The ~1H NMR spectra of the products provide evidence for the presence of N→Sn intramolecular coordination.The formation of dichlorobisaryltin(Ⅳ)as a unique product probably arises from the N→Sn intramolecular coordination which results in the increasing of the stability of the molecule.展开更多
The hydrothermal reaction of 5-methoxyisophthalic acid(MeO-H2ip), 1,3-bis(2-methylimidazol-1-yl)propane(bmip) and Zn(NO3)2·6H2O in the presence of NaOCH3 gave rise to a three-dimensional(3-D) metal-orga...The hydrothermal reaction of 5-methoxyisophthalic acid(MeO-H2ip), 1,3-bis(2-methylimidazol-1-yl)propane(bmip) and Zn(NO3)2·6H2O in the presence of NaOCH3 gave rise to a three-dimensional(3-D) metal-organic framework containing octanuclear Zn(II) units, [Zn4(MeO-ip)3(OH)2(bmip)]n. Single-crystal X-ray diffraction analysis reveals that the complex crystallizes in the triclinic space group P1 with a = 11.348(3), b = 14.163(4), c = 15.088(4) , α = 108.537(2), β = 106.542(2), γ = 103.106(1)o, V = 2065.4(9) -3, Z = 2, Mr = 334.62, Dc = 1.740 g·cm-(-3), μ = 2.375 mm-(-1), S = 1.015, F(000) = 1096, the final R = 0.0272 and w R = 0.0715 for 8929 observed reflections(I 〉 2σ(I)). The complex is thermally stable up to 370 oC, and exhibits photoluminescent emission at 450 nm on 350 nm excitation.展开更多
The electrochemical nature of reaction between melt and slag in a closed system was worked out. Experimental results demonstrated that both the rate and reaction extent increase when the electronic conductor or voltag...The electrochemical nature of reaction between melt and slag in a closed system was worked out. Experimental results demonstrated that both the rate and reaction extent increase when the electronic conductor or voltage was applied between melt and slag. The bigger the contact area of the conductor with melts is, the faster the reaction rate is. With the increase of applied voltage which is beneficial for electron's migration between metal and slags, the rate and extent of reaction increase.展开更多
Reported here are several new calculation methods for the inner-sphere reorganization energy of hydrated metal ions involved in electron transfer processes.It is based on the self-exchange model of reorganization and ...Reported here are several new calculation methods for the inner-sphere reorganization energy of hydrated metal ions involved in electron transfer processes.It is based on the self-exchange model of reorganization and utilizes the more exact potential functions between central metal ion and the inner-sphere ligands.The parameters involved are determined via the spectroscopic and thermodynamic data.The predictions of the inner-sphere reorganization energies from those models agree well with the photoemission experimental results.展开更多
Oxygen evolution reaction(OER) is one of the most important reactions in the energy storage devices such as metal–air batteries and unitized regenerative fuel cells(URFCs). However, the kinetically sluggishness o...Oxygen evolution reaction(OER) is one of the most important reactions in the energy storage devices such as metal–air batteries and unitized regenerative fuel cells(URFCs). However, the kinetically sluggishness of OER and the high prices as well as the scarcity of the most active precious metal electrocatalysts are the major bottleneck in these devices. Developing low-cost non-precious metal catalysts with high activity and stability for OER is highly desirable. A facile, in situ template method combining the dodecyl benzene sulfuric acid sodium(SDBS) assisted hydrothermal process with subsequent high-temperature treatment was developed to prepare porous Co3O4 with improved surface area and hierarchical porous structure as precious catalysts alternative for oxygen evolution reaction(OER). Due to the unique structure, the as-prepared catalyst shows higher electrocatalytic activity than Co3O4 prepared by traditional thermal-decomposition method(noted as Co3O4-T) and commercial IrO2 catalyst for OER in 0.1M KOH aqueous solution. Moreover, it displays improved stability than Co3O4-T. The results demonstrate a highly efficient, scalable, and low cost method for developing highly active and stable OER electrocatalysts in alkaline solutions.展开更多
Some monosubstituted Keggin or Dawson anions nave been reporten by Hill to be "remarkably effective" catalysts for the epoxidation of alkenes, Hill, Finke and Neumann reported respectively that the transitio...Some monosubstituted Keggin or Dawson anions nave been reporten by Hill to be "remarkably effective" catalysts for the epoxidation of alkenes, Hill, Finke and Neumann reported respectively that the transition metal monosubstituted heteropolyanions [PW;O;M(H;O)]";, [P;W;O;M(L)]"- and [SiW;O;Ru(H;O)];have an ability to catalyze the epoxidation of alkenes. And the undecatungstotitanates with one kind of transition metal have展开更多
In the presence of active metal bismuth (Bi) which was prepared from the combination of bismuth trichloride and sodium borohydride,aldehydes have been found to react with allyl bromide in aqueous media,and the corresp...In the presence of active metal bismuth (Bi) which was prepared from the combination of bismuth trichloride and sodium borohydride,aldehydes have been found to react with allyl bromide in aqueous media,and the corresponding homoallylic alcohols were obtained in excellent yields with high chemo-and stereoselectivity.展开更多
The development of efficient and stable non-noble metal-based electrocatalysts for the oxygen evolution reaction (OER) is one of the essential challenges for the upcoming hydrogen economy. Herein, three-dimensional ...The development of efficient and stable non-noble metal-based electrocatalysts for the oxygen evolution reaction (OER) is one of the essential challenges for the upcoming hydrogen economy. Herein, three-dimensional (3D) mesoporous nickel iron selenide with rose-like microsphere architecture was directly grown on Ni foam via a successive two-step hydrotherrnal method. The unique 3D mesoporous rose-like morphology leads to a higher number of active sites as well as fast mass and electron transport through the entire electrode, and facilitates the release of 02 bubbles formed during the OER catalysis. As a result, the synthesized Ni0.76Fe0.24Se exhibits superior OER performances, with an ultralow overpotential of 197 mV needed to produce a current density of 10 mA.cm-2 in 1 M KOH, outperforming all transition metal selenide OER catalysts reported to date.展开更多
With or without activation or inhibition of metal ion,the power-time curves of amylase catalyzed reaction were determined by a 2277 thermal activity monitor (Sweden). The Michaelis constant ( K ),apparent Michaelis co...With or without activation or inhibition of metal ion,the power-time curves of amylase catalyzed reaction were determined by a 2277 thermal activity monitor (Sweden). The Michaelis constant ( K ),apparent Michaelis constant ( K _m),maximum velocity ( v _m) and apparent maximum velocity ( v _ am ) of amylase catalyzed reaction were obtained using thermokinetic theory and reduced extent method. On the basis of data obtained,the following relationships between K _m and concentration of metal ion ( c ) were established: for inhibitor of Ni 2+ K _m=2.9648×10 -3 -1.3912×10 -4 cR =0.9998for inhibitor of Co 2+ K _m=1.0227×10 -3 +8.2676×10 -6 cR =0.9955for activator of Ca 2+ K _m=1.0630×10 -7 c 2-1.8311×10 -6 c +9.3058×10 -6 R =0.9999for activator of Li + K _m=5.6300×10 -8 c 2-1.5329×10 -6 c +1.2662×10 -5 R =0.9999 The K _m- c relationships show a strenuous inhibitory effect for Ni 2+ and a strenuous active effect for Ca 2+ .展开更多
An intermolecular two C-C bond formation procedure for the synthesis of carbocycles mediated by hyperva-lent iodine(III)reagents was developed.This metal free protocol provided a new approach for the synthesis of use-...An intermolecular two C-C bond formation procedure for the synthesis of carbocycles mediated by hyperva-lent iodine(III)reagents was developed.This metal free protocol provided a new approach for the synthesis of use-ful substituted 1-amino-2-naphthoic acid derivatives via benzannulation reactions.Various N-unsubstituted and N-alkyl substituted aromatic enamines with terminal alkynes and non-terminal alkynes can be converted into corre-sponding 1-amino-2-naphthoic acid derivatives under mild reaction conditions.When meta-substituted phenyl enamines were employed in the reaction,two cyclization paths were detected in the reaction and ortho-cyclization products were the only or major products.Good functional group tolerance,readily available material and high atom utilization efficiency make this method a potential procedure which may find broad application in organic synthesis.展开更多
Cobalt oxide doped titanate nanotubes are synthesized with a simple hydrothermal treatment of mixed Co3O4 and TiO2 powders. The formed tubular nanostructure, chemical composition,and the elemental distribution are ana...Cobalt oxide doped titanate nanotubes are synthesized with a simple hydrothermal treatment of mixed Co3O4 and TiO2 powders. The formed tubular nanostructure, chemical composition,and the elemental distribution are analyzed using TEM, BET, FTIR, XRD, and XPS. The electrocatalytic activity towards oxygen evolution reactions and photodegradation against Rhodamine B are investigated. It has been found out that the oxygen evolutions starts at 0.8 V and reaches 0.98 mA ·cm^-1 at 1.4 V vs. SCE. For photodegradation of Rhodamine B, the concentration decreased to 24% after 1 h irradiation using the sample with a mass percentage of 5% cobalt. The results demonstrate that the cobalt oxide doped titanate nanotubes are good candidates as electrocatalysts and photocatalytic materials.展开更多
Microtubes/rods of the layered metal hydroxide salt compound Cd2(OH)3(DS)·nH2O, where DS stands for dodecyl sulfate sandwiched between two adjacent inorganic sheets, have been synthesized for the first time t...Microtubes/rods of the layered metal hydroxide salt compound Cd2(OH)3(DS)·nH2O, where DS stands for dodecyl sulfate sandwiched between two adjacent inorganic sheets, have been synthesized for the first time through a mild hydrothermal reaction route. The microtubes/rods have a diameter of about 1 μm and a length ranging from several microns to 20μm. The growth process of microtubes/rods under the experimental conditions employed follows a dissolution-recrystallization route.展开更多
文摘The dehydrogenation reaction of H2S by the ^3Σ^- ground state of VS^+: VS^+ + H2S → VS2^+ + H2 has been studied by using Density Functional Theory (DPT) at the B3LYP/DZVP level. It is found that the reaction proceeds along two possible pathways (A and B) yielding two isomer dehydrogenation products VS2^+-1 (^3B2) and VS2^+-2 (^3A1), respectively. For both pathways, the reaction has a two-step-reaction mechanism that involves the migration of two hydrogen atoms from S2 to V^+, respectively. The migration of the second hydrogen via TS3 and that of the first via TS4 are the rate-determining steps for pathways A and B, respectively. The activation energy is 17.4 kcal/mol for pathway A and 22.8 kcal/mol for pathway B relative to the reactants. The calculated reaction heat of 9.9 kcal/mol indicates the endothermicity of pathway A and that of -11.9 kcal/mol suggests the exothermicity of pathway B.
基金This work is supported by the Ministry of Sci-ence and Technology of China(No.2016YFA0200603,No.2017YFA0204904)the Strategic Priority Re-search Program of Chinese Academy of Sciences(XDB36000000)+1 种基金the National Natural Science Foun-dation of China(No.21972129)Anhui Initiative in Quantum Information Technologies(AHY090000).
文摘Metalation reac-tion of metal-free phthalocyanine molecule with Co atom adsorbed on Au(111)surface has been studied in situ at single atom/molecule scale by low-temperature scanning tunneling microscopy(STM)experiment combined with simulations based on density function theory calculations.Through manipulations using STM tip,we showed a controlled manner to have a single metal-free phthalocyanine molecule react with a Co atom to form Co phthalocyanine molecule.In this reaction process,an intermediate state originating from π-d interaction between the metal-free phthalocyanine molecule and Co atom has been identi ed.Moreover,we also revealed that the redox reaction represented as bond breaking and bond forming relative to the Co and pyrrolic N atoms,not pyrrolic H atoms,is a key process for dehydrogenation and metalation reaction.Our DFT calculations provided theoretical supporting for the above conclusions,and further understanding of the related mechanisms.
文摘The kinetics and the mechanism of the formation reactions of M(PnAO)^(2+)(M=Ni,Co,Cu)were studied with UV Spectrophotometer and Stopped Flow Spectrophotometer and a three steps mechanism was suggested.
文摘The transmetallation reaction of 4 Schiff base type arylmercury compounds with metallic tin has been carried out in refluxing xylene.It was found that the reaction proceeds in the same manner as that of chloro[2-(phenylazo)phenyl]mercury(Ⅱ) to give dichlorobisaryltin(Ⅳ).The ~1H NMR spectra of the products provide evidence for the presence of N→Sn intramolecular coordination.The formation of dichlorobisaryltin(Ⅳ)as a unique product probably arises from the N→Sn intramolecular coordination which results in the increasing of the stability of the molecule.
基金supported by the Natural Science Foundation of Fujian Province(2015J01038)Provincial Education Department of Fujian(JA12070)State Key Laboratory of Structural Chemistry(20150015)
文摘The hydrothermal reaction of 5-methoxyisophthalic acid(MeO-H2ip), 1,3-bis(2-methylimidazol-1-yl)propane(bmip) and Zn(NO3)2·6H2O in the presence of NaOCH3 gave rise to a three-dimensional(3-D) metal-organic framework containing octanuclear Zn(II) units, [Zn4(MeO-ip)3(OH)2(bmip)]n. Single-crystal X-ray diffraction analysis reveals that the complex crystallizes in the triclinic space group P1 with a = 11.348(3), b = 14.163(4), c = 15.088(4) , α = 108.537(2), β = 106.542(2), γ = 103.106(1)o, V = 2065.4(9) -3, Z = 2, Mr = 334.62, Dc = 1.740 g·cm-(-3), μ = 2.375 mm-(-1), S = 1.015, F(000) = 1096, the final R = 0.0272 and w R = 0.0715 for 8929 observed reflections(I 〉 2σ(I)). The complex is thermally stable up to 370 oC, and exhibits photoluminescent emission at 450 nm on 350 nm excitation.
文摘The electrochemical nature of reaction between melt and slag in a closed system was worked out. Experimental results demonstrated that both the rate and reaction extent increase when the electronic conductor or voltage was applied between melt and slag. The bigger the contact area of the conductor with melts is, the faster the reaction rate is. With the increase of applied voltage which is beneficial for electron's migration between metal and slags, the rate and extent of reaction increase.
基金Supported by the Natural Science Foundation of Shandong Province
文摘Reported here are several new calculation methods for the inner-sphere reorganization energy of hydrated metal ions involved in electron transfer processes.It is based on the self-exchange model of reorganization and utilizes the more exact potential functions between central metal ion and the inner-sphere ligands.The parameters involved are determined via the spectroscopic and thermodynamic data.The predictions of the inner-sphere reorganization energies from those models agree well with the photoemission experimental results.
基金supported by the Youth Innovation Promotion Association(no.2015147)CAS and National Program on Key Basic Research Project(973 Program,2012CB215500)+1 种基金the Outstanding Youngest Scientist FoundationChinese Academy of Sciences(CAS)
文摘Oxygen evolution reaction(OER) is one of the most important reactions in the energy storage devices such as metal–air batteries and unitized regenerative fuel cells(URFCs). However, the kinetically sluggishness of OER and the high prices as well as the scarcity of the most active precious metal electrocatalysts are the major bottleneck in these devices. Developing low-cost non-precious metal catalysts with high activity and stability for OER is highly desirable. A facile, in situ template method combining the dodecyl benzene sulfuric acid sodium(SDBS) assisted hydrothermal process with subsequent high-temperature treatment was developed to prepare porous Co3O4 with improved surface area and hierarchical porous structure as precious catalysts alternative for oxygen evolution reaction(OER). Due to the unique structure, the as-prepared catalyst shows higher electrocatalytic activity than Co3O4 prepared by traditional thermal-decomposition method(noted as Co3O4-T) and commercial IrO2 catalyst for OER in 0.1M KOH aqueous solution. Moreover, it displays improved stability than Co3O4-T. The results demonstrate a highly efficient, scalable, and low cost method for developing highly active and stable OER electrocatalysts in alkaline solutions.
基金Supported by the National Natural Science Foundation of ChinaLaboratory of Apphed spectroscopy
文摘Some monosubstituted Keggin or Dawson anions nave been reporten by Hill to be "remarkably effective" catalysts for the epoxidation of alkenes, Hill, Finke and Neumann reported respectively that the transition metal monosubstituted heteropolyanions [PW;O;M(H;O)]";, [P;W;O;M(L)]"- and [SiW;O;Ru(H;O)];have an ability to catalyze the epoxidation of alkenes. And the undecatungstotitanates with one kind of transition metal have
文摘In the presence of active metal bismuth (Bi) which was prepared from the combination of bismuth trichloride and sodium borohydride,aldehydes have been found to react with allyl bromide in aqueous media,and the corresponding homoallylic alcohols were obtained in excellent yields with high chemo-and stereoselectivity.
基金This work was financially supported by the National Natural Science Foundation of China (Nos. 21571145 and 21633008), the Fundamental Research Funds for the Central Universities and Large-scale Instrument and Equipment Sharing Foundation of Wuhan University.
文摘The development of efficient and stable non-noble metal-based electrocatalysts for the oxygen evolution reaction (OER) is one of the essential challenges for the upcoming hydrogen economy. Herein, three-dimensional (3D) mesoporous nickel iron selenide with rose-like microsphere architecture was directly grown on Ni foam via a successive two-step hydrotherrnal method. The unique 3D mesoporous rose-like morphology leads to a higher number of active sites as well as fast mass and electron transport through the entire electrode, and facilitates the release of 02 bubbles formed during the OER catalysis. As a result, the synthesized Ni0.76Fe0.24Se exhibits superior OER performances, with an ultralow overpotential of 197 mV needed to produce a current density of 10 mA.cm-2 in 1 M KOH, outperforming all transition metal selenide OER catalysts reported to date.
基金ProjectsupportedbytheNaturalScienceFoundationofShandongProvince (No .Y2 0 0 0B0 3 )
文摘With or without activation or inhibition of metal ion,the power-time curves of amylase catalyzed reaction were determined by a 2277 thermal activity monitor (Sweden). The Michaelis constant ( K ),apparent Michaelis constant ( K _m),maximum velocity ( v _m) and apparent maximum velocity ( v _ am ) of amylase catalyzed reaction were obtained using thermokinetic theory and reduced extent method. On the basis of data obtained,the following relationships between K _m and concentration of metal ion ( c ) were established: for inhibitor of Ni 2+ K _m=2.9648×10 -3 -1.3912×10 -4 cR =0.9998for inhibitor of Co 2+ K _m=1.0227×10 -3 +8.2676×10 -6 cR =0.9955for activator of Ca 2+ K _m=1.0630×10 -7 c 2-1.8311×10 -6 c +9.3058×10 -6 R =0.9999for activator of Li + K _m=5.6300×10 -8 c 2-1.5329×10 -6 c +1.2662×10 -5 R =0.9999 The K _m- c relationships show a strenuous inhibitory effect for Ni 2+ and a strenuous active effect for Ca 2+ .
基金support of this work by Baoji University of Arts and Sciences(No.ZK15046).
文摘An intermolecular two C-C bond formation procedure for the synthesis of carbocycles mediated by hyperva-lent iodine(III)reagents was developed.This metal free protocol provided a new approach for the synthesis of use-ful substituted 1-amino-2-naphthoic acid derivatives via benzannulation reactions.Various N-unsubstituted and N-alkyl substituted aromatic enamines with terminal alkynes and non-terminal alkynes can be converted into corre-sponding 1-amino-2-naphthoic acid derivatives under mild reaction conditions.When meta-substituted phenyl enamines were employed in the reaction,two cyclization paths were detected in the reaction and ortho-cyclization products were the only or major products.Good functional group tolerance,readily available material and high atom utilization efficiency make this method a potential procedure which may find broad application in organic synthesis.
基金Supported by the National Natural Science Foundation of China(21576216,51372192)the Innovation Foundation from China Southern Power Grid(GDKJQQ20152050)
文摘Cobalt oxide doped titanate nanotubes are synthesized with a simple hydrothermal treatment of mixed Co3O4 and TiO2 powders. The formed tubular nanostructure, chemical composition,and the elemental distribution are analyzed using TEM, BET, FTIR, XRD, and XPS. The electrocatalytic activity towards oxygen evolution reactions and photodegradation against Rhodamine B are investigated. It has been found out that the oxygen evolutions starts at 0.8 V and reaches 0.98 mA ·cm^-1 at 1.4 V vs. SCE. For photodegradation of Rhodamine B, the concentration decreased to 24% after 1 h irradiation using the sample with a mass percentage of 5% cobalt. The results demonstrate that the cobalt oxide doped titanate nanotubes are good candidates as electrocatalysts and photocatalytic materials.
基金the National Natural Science Foun-dation of China for financial support
文摘Microtubes/rods of the layered metal hydroxide salt compound Cd2(OH)3(DS)·nH2O, where DS stands for dodecyl sulfate sandwiched between two adjacent inorganic sheets, have been synthesized for the first time through a mild hydrothermal reaction route. The microtubes/rods have a diameter of about 1 μm and a length ranging from several microns to 20μm. The growth process of microtubes/rods under the experimental conditions employed follows a dissolution-recrystallization route.