In order to ameliorate the electrochemical hydrogen storage performance of La-Mg-Ni system A2B7-type electrode alloys, a small amount of Si was added. The La0.8Mg0.2Ni3.3Co0.2Six （x=0-0.2） electrode alloys were prep...In order to ameliorate the electrochemical hydrogen storage performance of La-Mg-Ni system A2B7-type electrode alloys, a small amount of Si was added. The La0.8Mg0.2Ni3.3Co0.2Six （x=0-0.2） electrode alloys were prepared by casting and annealing. The effects of adding Si on the structure and electrochemical hydrogen storage characteristics of the alloys were investigated systematically. The results indicate that the as-cast and annealed alloys hold multiple structures, involving two major phases of （La, Mg）2Ni7 with a Ce2Ni7-type hexagonal structure and LaNi5 with a CaCu5-type hexagonal structure as well as one residual phase LaNi3. The addition of Si results in a decrease in （La, Mg）2Ni7 phase and an increase in LaNi5 phase without changing the phase structure of the alloys. What is more, it brings on an obvious effect on electrochemical hydrogen storage characteristics of the alloys. The discharge capacities of the as-cast and annealed alloys decline with the increase of Si content, but their cycle stabilities clearly grow under the same condition. Furthermore, the measurements of the high rate discharge ability, the limiting current density, hydrogen diffusion coefficient as well as electrochemical impedance spectra all indicate that the electrochemical kinetic properties of the electrode alloys first increase and then decrease with the rising of Si content.展开更多
Seven electron-deficient A_2 B type H_3-triarylcorroles have been synthesized and characterized. The solvent dependence of the electronic absorption and magnetic circular dichroism（MCD） spectra and a series of TD-DF...Seven electron-deficient A_2 B type H_3-triarylcorroles have been synthesized and characterized. The solvent dependence of the electronic absorption and magnetic circular dichroism（MCD） spectra and a series of TD-DFT calculations have been used to analyze trends in the electronic structures. Significant differences are observed in the optical spectra when solvents of differing polarity are used,which can be assigned to the effect of NH-tautomerism.展开更多
The title compounds, 2-（3,3＇-bithiophen-2,2＇-yl）dibenzothiazole （BTDB） and 2-（dithieno[2,3-b：3＇,2＇-d]thiophen-2,5-yl）dibenzothiazole （DTTDB）, have been synthesized and characterized by FT-IR, NMR, MS, HRM...The title compounds, 2-（3,3＇-bithiophen-2,2＇-yl）dibenzothiazole （BTDB） and 2-（dithieno[2,3-b：3＇,2＇-d]thiophen-2,5-yl）dibenzothiazole （DTTDB）, have been synthesized and characterized by FT-IR, NMR, MS, HRMS and X-ray single-crystal diffraction. The crystal of BTDB crystallizes in triclinic, space group P1 with a = 9.2207（17）, b = 10.453（2）, c = 10.969（2） A, V= 981.2（3） A3 and Z = 2. Crystal data of DTTDB： orthorhombic system, space group Pbcn with a = 4.5290（8）, b = 13.576（3）, c = 32.033（6） A, V= 1969.6（6） A3 and Z = 4.展开更多
The title compound ethyl 2-（6-（1,3-dioxo-4,5,6,7-tetrahydro-lH-isoindol-2（3H）- yl）-7-fluoro-3-oxo-2H-benzo[b][1,4]oxazin-4（3H）-yl） butanoate 3 was synthesized by the reaction of ethyl 2-（6-amino-7-fluoro-3-ox...The title compound ethyl 2-（6-（1,3-dioxo-4,5,6,7-tetrahydro-lH-isoindol-2（3H）- yl）-7-fluoro-3-oxo-2H-benzo[b][1,4]oxazin-4（3H）-yl） butanoate 3 was synthesized by the reaction of ethyl 2-（6-amino-7-fluoro-3-oxo-2H-benzo[b][1,4]oxazin-4（3H）-yl） butanoate with 4,5,6,7- tetraydrophthalic anhydride, and its structure was determined by X-ray single-crystal diffraction. The crystal belongs to the monoclinic system, space group P2 1/n with a = 9.3469（2）, b = 16.7715（5）, c = 13.7153（4） A, β= 104.9680（10）°, μ = 0.107 mm^-1, Mr = 430.42, V= 2077.08（10） ,A3, Z= 4, Dc = 1.376 g/cm3, F（000） = 904, T= 296（2） K, R = 0.0508 and wR = 0.1478.展开更多
New Schiff base Macrocyclic compound of 2,3: 11, 12:20, 21:29, 30-tetrabenzo-1,13,16,19,31,34-hexaoxa-5,6,8,9,23,24,26,27-octaaza-7,25-dithione-2,3:4,5:9,10:11,12:22, 23:27,28:29,30 cyclo-[36]ene (thione2B4[36] ene-O6...New Schiff base Macrocyclic compound of 2,3: 11, 12:20, 21:29, 30-tetrabenzo-1,13,16,19,31,34-hexaoxa-5,6,8,9,23,24,26,27-octaaza-7,25-dithione-2,3:4,5:9,10:11,12:22, 23:27,28:29,30 cyclo-[36]ene (thione2B4[36] ene-O6N8) containing THF has been prepared. It crystallizes in the monoclinic, space group P21/n. with parameters a=9.829(5) b=24.23(1), c=10.181(9), β=92.93(5)°, Z=2, V=2422(3)3, Dc=1.25gcm-3. Data collection: Rigaku AFC-5R diffractometer,(MoKα, λ=0.71069), ω /2θ scans. θmax=25°, empirical absorption correction, 4658 measured reflections, 4387 independent, 1743 observed reflections [I≥3σ(I)]. The final R=0.056. RW=0.069,S=1 .54, (Δ/σ)max=0.01,Δρmax=0.36e-3.展开更多
The title compound 2-benzylamino-6-methyl-3-cyano-8-phenyl-5H-bispyrazolo[3,4-d,3＇,2＇-b]pyrimidine crystallizes in orthorhombic, space group Pbca with a = 17.945（7）, b =10.862（4）, c = 19.481（7） A°, β = 9...The title compound 2-benzylamino-6-methyl-3-cyano-8-phenyl-5H-bispyrazolo[3,4-d,3＇,2＇-b]pyrimidine crystallizes in orthorhombic, space group Pbca with a = 17.945（7）, b =10.862（4）, c = 19.481（7） A°, β = 90°, Z = 8, V = 1151.8（4） A°^3, Mr = 379.43, Dx = 1.327 g/cm^3,μ（MoKa） = 0.084 mm^-1, F（000） = 1584, the final R = 0.0513 and wR = 0.1128 for 2608 observed reflections （I 〉 2σ（I））. X-ray analysis reveals that the tricyclic portion of the molecule is effectively planar. In addition, there exist three intermolecular hydrogen bonds.展开更多
C100H78, (A: C36H28, B: C28H22) Mr = 1279. 74, monoclinic, P21/a, a=17. 282(3), b=10. 669(4), c= 19, 927(3) A , β =102. 99(1)°,V = 3580. 1(2) A3, Z=2, μ(MoKα) = 0. 623cm-1, F(000) = 1356, Dc=1. 187g/cm3, room ...C100H78, (A: C36H28, B: C28H22) Mr = 1279. 74, monoclinic, P21/a, a=17. 282(3), b=10. 669(4), c= 19, 927(3) A , β =102. 99(1)°,V = 3580. 1(2) A3, Z=2, μ(MoKα) = 0. 623cm-1, F(000) = 1356, Dc=1. 187g/cm3, room temperature. The final R=0. 084, Rw = 0. 086 for 1255 independent observed reflections (I≥3σ(I)). Owing to the existence of 1,6,7, 8-Tetraphenyl (3,4-benzo)-bicyclo[4, 2, 0]octa-7-ene(A) , cis, cts-1, 2, 3, 4-Tetraphenylbutadiene (B) in A2B can take the different conformation from the one in the pure B crystal. The reason of the formation of this molecular compound crystal is put forward.展开更多
杂原子掺杂可以调节电子结构以调整中间体吸附并优化反应路径,是设计高效CO_(2)还原反应(CO_(2)RR)催化剂的有应用前景的方法.B原子是常用的掺杂剂,引入B原子可以有效打破*COOH和OCHO*中间体的吉布斯自由能线性关系,并且可以通过与CO_(2...杂原子掺杂可以调节电子结构以调整中间体吸附并优化反应路径,是设计高效CO_(2)还原反应(CO_(2)RR)催化剂的有应用前景的方法.B原子是常用的掺杂剂,引入B原子可以有效打破*COOH和OCHO*中间体的吉布斯自由能线性关系,并且可以通过与CO_(2)中O原子结合来增强CO_(2)吸附能力.B掺杂碳材料、单金属和金属氧化物的研究结果表明,B原子掺杂催化剂的CO_(2)RR活性和/或选择性有明显提高,然而多数报道的单个活性位点的B掺杂催化剂仅表现出在相对狭窄的电位范围内的CO_(2)RR高性能,设计制备CO_(2)RR的宽电位高选择性催化剂仍是巨大挑战.研究表明,合金化是提供多种类的活性位点相互协调和增强催化剂固有活性,进而改善CO_(2)RR性能并调节产物分布的可行策略.引入B原子到合金中以调节电子结构,最终优化关键中间体吸附的活性位点,对于寻找具有宽电位窗口的先进催化剂具有重要意义.本文提出了一种通过B掺杂调节CuIn合金电子结构以实现宽电位高选择性的电子工程策略.所制得的B掺杂CuIn合金(CuIn(B))在–0.6 V(vs.RHE)时表现出99%的CO法拉第效率(FECO),并在一个宽的阴极电化学窗口(400 m V)内保持了超过90%的较高FECO.同时,采用X射线光电子能谱(XPS)和CO_(2)吸附实验等手段研究了CuIn(B)性能提升的原因,结果表明,B原子与CuIn之间存在强烈的相互作用,改变了CuIn的电子结构.CO_(2)吸附结果表明,CuIn(B)比CuIn拥有更强的CO_(2)吸附能力,证明它具有潜在的快速CO_(2)RR反应动力学.进一步通过密度泛函理论(DFT)模拟研究了催化剂的热力学反应能量学以揭示CO_(2)RR机制,结果表明,*COOH更倾向于在CuIn(B)上形成,且*CO与CuIn(B)催化位点的结合强度最佳,更利于CO_(2)还原反应为CO,而CuIn更利于作为HER的活性位点;决速步骤是*CO中间体向CO转移,以实现高CO选择性;热力学限制电位研究表明,CuIn(B)大大提高了CO_(2)到CO转化的选择性.随后通过差分电荷密度研究也进一步证明了电荷转移过程是从CuIn位点到B位点.此外,根据d带理论,催化剂中Cu和In原子的投影态密度和d带中心(Ed)研究进一步证明了催化剂结构中的电子价态的变化,与XPS结果相符;引入B可以优化催化剂的电子结构,从而调节催化剂和中间体之间的结合能力,实现了CO_(2)RR在宽电位范围内的高活性和选择性.综上,本文对于电化学CO_(2)RR机理的基础理解和其实际应用具有促进作用.展开更多
The crystal structure of 3-(4-methoxyphenyl)- l-methyl-pyrrolo[2,1-b] benzothiazole (C18H15NOS, Mr = 293. 38) has been determined. The title com-pound crystallizes in monoclinic space group P21/n with cell dimensions ...The crystal structure of 3-(4-methoxyphenyl)- l-methyl-pyrrolo[2,1-b] benzothiazole (C18H15NOS, Mr = 293. 38) has been determined. The title com-pound crystallizes in monoclinic space group P21/n with cell dimensions a= l. 3308(4)'b=0. 8403(2), c= l. 4l47 (4)nm, β= 68. 08(2)°, V= 1. 4676(5)nm3, Z= 4, Dc=1. 328g. cm-3, F(000) = 6l6,μ= l8. 18cm-l, CuKa(η= O. 154l8nm). The struc-ture was solved by direct methods and refined by full matrix least-Squares. The finaldiscrepancy factor is 0. 053 for 1522 observed reflections. The molecular backbone is anearly planar tricyclic system.展开更多
基金Projects(50961009,51161015)supported by the National Natural Science Foundation of ChinaProject(2011AA03A408)supported by the High-tech Research and Development Program of ChinaProjects(2011ZD10,2010ZD05)supported by the Natural Science Foundation of Inner Mongolia,China
文摘In order to ameliorate the electrochemical hydrogen storage performance of La-Mg-Ni system A2B7-type electrode alloys, a small amount of Si was added. The La0.8Mg0.2Ni3.3Co0.2Six （x=0-0.2） electrode alloys were prepared by casting and annealing. The effects of adding Si on the structure and electrochemical hydrogen storage characteristics of the alloys were investigated systematically. The results indicate that the as-cast and annealed alloys hold multiple structures, involving two major phases of （La, Mg）2Ni7 with a Ce2Ni7-type hexagonal structure and LaNi5 with a CaCu5-type hexagonal structure as well as one residual phase LaNi3. The addition of Si results in a decrease in （La, Mg）2Ni7 phase and an increase in LaNi5 phase without changing the phase structure of the alloys. What is more, it brings on an obvious effect on electrochemical hydrogen storage characteristics of the alloys. The discharge capacities of the as-cast and annealed alloys decline with the increase of Si content, but their cycle stabilities clearly grow under the same condition. Furthermore, the measurements of the high rate discharge ability, the limiting current density, hydrogen diffusion coefficient as well as electrochemical impedance spectra all indicate that the electrochemical kinetic properties of the electrode alloys first increase and then decrease with the rising of Si content.
基金financially supported by the National Natural Science Foundation of China(No.21171076)Natural Science Foundation of Jiangsu Province(No.BK20160499)to XL and WZ and an NRF of South Africa CSUR grant(uid:93627)to JM
文摘Seven electron-deficient A_2 B type H_3-triarylcorroles have been synthesized and characterized. The solvent dependence of the electronic absorption and magnetic circular dichroism（MCD） spectra and a series of TD-DFT calculations have been used to analyze trends in the electronic structures. Significant differences are observed in the optical spectra when solvents of differing polarity are used,which can be assigned to the effect of NH-tautomerism.
基金supported by the National Natural Science Foundation of China (20972041)Program for Innovation Scientists and Technicians Troop Construction Projects of Henan Province (104100510011)the Program of Henan University (SBGJ090506)
文摘The title compounds, 2-（3,3＇-bithiophen-2,2＇-yl）dibenzothiazole （BTDB） and 2-（dithieno[2,3-b：3＇,2＇-d]thiophen-2,5-yl）dibenzothiazole （DTTDB）, have been synthesized and characterized by FT-IR, NMR, MS, HRMS and X-ray single-crystal diffraction. The crystal of BTDB crystallizes in triclinic, space group P1 with a = 9.2207（17）, b = 10.453（2）, c = 10.969（2） A, V= 981.2（3） A3 and Z = 2. Crystal data of DTTDB： orthorhombic system, space group Pbcn with a = 4.5290（8）, b = 13.576（3）, c = 32.033（6） A, V= 1969.6（6） A3 and Z = 4.
基金Supported by the National Natural Science Foundation of China (20872033, 20575019)Natural Science Foundation of Hunan Province (07JJ1003)+1 种基金Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China) (KLCBTCMR2008-14)Scientific Research Fund of Science and Technology Department of Hunan Province (No. 2006GK3067)
文摘The title compound ethyl 2-（6-（1,3-dioxo-4,5,6,7-tetrahydro-lH-isoindol-2（3H）- yl）-7-fluoro-3-oxo-2H-benzo[b][1,4]oxazin-4（3H）-yl） butanoate 3 was synthesized by the reaction of ethyl 2-（6-amino-7-fluoro-3-oxo-2H-benzo[b][1,4]oxazin-4（3H）-yl） butanoate with 4,5,6,7- tetraydrophthalic anhydride, and its structure was determined by X-ray single-crystal diffraction. The crystal belongs to the monoclinic system, space group P2 1/n with a = 9.3469（2）, b = 16.7715（5）, c = 13.7153（4） A, β= 104.9680（10）°, μ = 0.107 mm^-1, Mr = 430.42, V= 2077.08（10） ,A3, Z= 4, Dc = 1.376 g/cm3, F（000） = 904, T= 296（2） K, R = 0.0508 and wR = 0.1478.
文摘New Schiff base Macrocyclic compound of 2,3: 11, 12:20, 21:29, 30-tetrabenzo-1,13,16,19,31,34-hexaoxa-5,6,8,9,23,24,26,27-octaaza-7,25-dithione-2,3:4,5:9,10:11,12:22, 23:27,28:29,30 cyclo-[36]ene (thione2B4[36] ene-O6N8) containing THF has been prepared. It crystallizes in the monoclinic, space group P21/n. with parameters a=9.829(5) b=24.23(1), c=10.181(9), β=92.93(5)°, Z=2, V=2422(3)3, Dc=1.25gcm-3. Data collection: Rigaku AFC-5R diffractometer,(MoKα, λ=0.71069), ω /2θ scans. θmax=25°, empirical absorption correction, 4658 measured reflections, 4387 independent, 1743 observed reflections [I≥3σ(I)]. The final R=0.056. RW=0.069,S=1 .54, (Δ/σ)max=0.01,Δρmax=0.36e-3.
文摘The title compound 2-benzylamino-6-methyl-3-cyano-8-phenyl-5H-bispyrazolo[3,4-d,3＇,2＇-b]pyrimidine crystallizes in orthorhombic, space group Pbca with a = 17.945（7）, b =10.862（4）, c = 19.481（7） A°, β = 90°, Z = 8, V = 1151.8（4） A°^3, Mr = 379.43, Dx = 1.327 g/cm^3,μ（MoKa） = 0.084 mm^-1, F（000） = 1584, the final R = 0.0513 and wR = 0.1128 for 2608 observed reflections （I 〉 2σ（I））. X-ray analysis reveals that the tricyclic portion of the molecule is effectively planar. In addition, there exist three intermolecular hydrogen bonds.
基金The Project was supported by the National Science Foundation of China
文摘C100H78, (A: C36H28, B: C28H22) Mr = 1279. 74, monoclinic, P21/a, a=17. 282(3), b=10. 669(4), c= 19, 927(3) A , β =102. 99(1)°,V = 3580. 1(2) A3, Z=2, μ(MoKα) = 0. 623cm-1, F(000) = 1356, Dc=1. 187g/cm3, room temperature. The final R=0. 084, Rw = 0. 086 for 1255 independent observed reflections (I≥3σ(I)). Owing to the existence of 1,6,7, 8-Tetraphenyl (3,4-benzo)-bicyclo[4, 2, 0]octa-7-ene(A) , cis, cts-1, 2, 3, 4-Tetraphenylbutadiene (B) in A2B can take the different conformation from the one in the pure B crystal. The reason of the formation of this molecular compound crystal is put forward.
文摘杂原子掺杂可以调节电子结构以调整中间体吸附并优化反应路径,是设计高效CO_(2)还原反应(CO_(2)RR)催化剂的有应用前景的方法.B原子是常用的掺杂剂,引入B原子可以有效打破*COOH和OCHO*中间体的吉布斯自由能线性关系,并且可以通过与CO_(2)中O原子结合来增强CO_(2)吸附能力.B掺杂碳材料、单金属和金属氧化物的研究结果表明,B原子掺杂催化剂的CO_(2)RR活性和/或选择性有明显提高,然而多数报道的单个活性位点的B掺杂催化剂仅表现出在相对狭窄的电位范围内的CO_(2)RR高性能,设计制备CO_(2)RR的宽电位高选择性催化剂仍是巨大挑战.研究表明,合金化是提供多种类的活性位点相互协调和增强催化剂固有活性,进而改善CO_(2)RR性能并调节产物分布的可行策略.引入B原子到合金中以调节电子结构,最终优化关键中间体吸附的活性位点,对于寻找具有宽电位窗口的先进催化剂具有重要意义.本文提出了一种通过B掺杂调节CuIn合金电子结构以实现宽电位高选择性的电子工程策略.所制得的B掺杂CuIn合金(CuIn(B))在–0.6 V(vs.RHE)时表现出99%的CO法拉第效率(FECO),并在一个宽的阴极电化学窗口(400 m V)内保持了超过90%的较高FECO.同时,采用X射线光电子能谱(XPS)和CO_(2)吸附实验等手段研究了CuIn(B)性能提升的原因,结果表明,B原子与CuIn之间存在强烈的相互作用,改变了CuIn的电子结构.CO_(2)吸附结果表明,CuIn(B)比CuIn拥有更强的CO_(2)吸附能力,证明它具有潜在的快速CO_(2)RR反应动力学.进一步通过密度泛函理论(DFT)模拟研究了催化剂的热力学反应能量学以揭示CO_(2)RR机制,结果表明,*COOH更倾向于在CuIn(B)上形成,且*CO与CuIn(B)催化位点的结合强度最佳,更利于CO_(2)还原反应为CO,而CuIn更利于作为HER的活性位点;决速步骤是*CO中间体向CO转移,以实现高CO选择性;热力学限制电位研究表明,CuIn(B)大大提高了CO_(2)到CO转化的选择性.随后通过差分电荷密度研究也进一步证明了电荷转移过程是从CuIn位点到B位点.此外,根据d带理论,催化剂中Cu和In原子的投影态密度和d带中心(Ed)研究进一步证明了催化剂结构中的电子价态的变化,与XPS结果相符;引入B可以优化催化剂的电子结构,从而调节催化剂和中间体之间的结合能力,实现了CO_(2)RR在宽电位范围内的高活性和选择性.综上,本文对于电化学CO_(2)RR机理的基础理解和其实际应用具有促进作用.
文摘The crystal structure of 3-(4-methoxyphenyl)- l-methyl-pyrrolo[2,1-b] benzothiazole (C18H15NOS, Mr = 293. 38) has been determined. The title com-pound crystallizes in monoclinic space group P21/n with cell dimensions a= l. 3308(4)'b=0. 8403(2), c= l. 4l47 (4)nm, β= 68. 08(2)°, V= 1. 4676(5)nm3, Z= 4, Dc=1. 328g. cm-3, F(000) = 6l6,μ= l8. 18cm-l, CuKa(η= O. 154l8nm). The struc-ture was solved by direct methods and refined by full matrix least-Squares. The finaldiscrepancy factor is 0. 053 for 1522 observed reflections. The molecular backbone is anearly planar tricyclic system.
