为探究溶剂对合成有机金属框架化合物的影响机制,采用实验和DFT理论计算相结合的方法,研究溶剂N,N-二甲基甲酰胺(DMF)和N-甲基-2-吡咯烷酮(NMP)对溶剂热法合成有机金属框架材料[Zn4O(BDC)3]8的影响及溶剂与框架间的微观作用机制。粉末X...为探究溶剂对合成有机金属框架化合物的影响机制,采用实验和DFT理论计算相结合的方法,研究溶剂N,N-二甲基甲酰胺(DMF)和N-甲基-2-吡咯烷酮(NMP)对溶剂热法合成有机金属框架材料[Zn4O(BDC)3]8的影响及溶剂与框架间的微观作用机制。粉末X射线衍射(XRD)和扫描电镜(SEM)结果表明,NMP在[Zn4O(BDC)3]8孔道中的吸附力较DMF的弱,NMP分子更容易从框架中脱除;热重(TG)和热重-红外联用(TGA/FT-IR)结果表明,以DMF为溶剂合成的[Zn4O(BDC)3]8的热分解温度和热稳定性较高;氮气等温吸附实验(BET)发现,以NMP为溶剂合成的[Zn4O(BDC)3]8的气体吸附性能更强,兰缪尔比表面积高于用DMF合成的[Zn4O(BDC)3]8。调控介电常数设定溶剂分别为NMP和DMF,用COSMO溶剂化方法对溶剂分子与框架化合物基本结构单元Zn4O(BDC)3间相互作用模型进行几何优化计算,发现溶剂设定为NMP时Zn4O(BDC)3优化结构的总能量较溶剂设定为DMF时的高8.6405 k J/mol,这说明DMF分子与Zn4O(BDC)3间的结合力强于NMP分子的,溶剂化作用降低了Zn与O间的离子性;用DMol3在GGA-BLYP/DN水平计算了DMF、NMP或DEF溶剂分子在[Zn4O(BDC)3]8晶体孔道中的相互作用,与DMF相比,NMP在孔道中能量状态稳定性较差,在能量状态角度上NMP应最容易从框架材料孔道中脱除。研究结果说明NMP更有利于合成性质良好的[Zn4O(BDC)3]8,与DMF相比NMP与框架结构基元间的作用力较弱。展开更多
A novel one-dimensional chain complex [Zn(dafo)2(H2O)2](NO3)2 was synthesized. It has been characterized by IR, UV, TGA, Elemental analysis and X-ray diffraction analysis. The crystal belongs to triclinic system, P1 s...A novel one-dimensional chain complex [Zn(dafo)2(H2O)2](NO3)2 was synthesized. It has been characterized by IR, UV, TGA, Elemental analysis and X-ray diffraction analysis. The crystal belongs to triclinic system, P1 space group. The Crystallographic data are: a = 0.702 7(14) nm, b = 0.828 95(17) nm, c = 10.225(2) nm, α = 95.02(3)°, β = 91.45(3)°, γ = 99.85(3)°. The crystal structure data indicate that the Zn(Ⅱ) ion was coordinated with the four nitrogen atoms of two dafo and two oxygen atoms of two coordination water molecules, respectively. The complex has a one-dimensional chain structure, which is formed by hydrogen bonds.展开更多
A\} novel two-dimensional coordination polymer Zn 3(PTC) 2(H 2O) 8·4H 2O was formed by \{Zn(CH 3COO) 2·\}2H 2O and 2-pyridine-1,3,5-tricarboxylate(H 3PTC) under the hydrothermal condition at 417 K and charac...A\} novel two-dimensional coordination polymer Zn 3(PTC) 2(H 2O) 8·4H 2O was formed by \{Zn(CH 3COO) 2·\}2H 2O and 2-pyridine-1,3,5-tricarboxylate(H 3PTC) under the hydrothermal condition at 417 K and characterized by fluorescence. The crystal structure of the compound was determined by single-crystal X-ray diffraction analyses. The six-coordinated Zinc(Ⅱ) center displays an octahedral geometry . The crystal is monoclinic and space group is P2(1)/c with a=0.722 70(14) nm, b= 1.866 7(4) nm , \{c=\}1.072 6(3) nm, α=90°, β=103.198(19)°, γ=90°, V=1.408 7(6) nm 3, Z=4, D c= 2.474 Mg/m 3, M r=828.536, μ=3.099 mm -1 , F(000)=1 060, GOF=0.892, R=0.061 3, wR= 0.133 9 .展开更多
Structural phase transitions of Zn4Sb3 and its substitutional compounds （Zn0.98M0.02）4Sb3 （M = Al, Ga and In） are investigated by electrical transport measurement and differential scanning calorimetry below room t...Structural phase transitions of Zn4Sb3 and its substitutional compounds （Zn0.98M0.02）4Sb3 （M = Al, Ga and In） are investigated by electrical transport measurement and differential scanning calorimetry below room temperature. The results indicate that both β→α and α→α′ phase transitions of Zn4Sb3 are reversible and exothermic processes, which may be explained as that both the transitions originate from the ordering of the disordered interstitial Zn and vacancies in regular sizes. The derived activation energies of β→α and α→α′ phase transition processes for Zn4Sb3 are E1 = 3.9 eV and E2 = 4.1 eV, respectively. Although no remarkable influence on activation energy E2 is observed after A1 doping, A1 substitution for Zn causes E1 to increase to 4.6 eV, implying its suppression of β←→α transition to a great extent. Moreover, it is found that both β←→α and α←→α′ transitions are completely prohibited by substitution of either In or Ga for Zn in Zn4Sb3. The underlying mechanisms for these phenomena are discussed.展开更多
The zinc 3-hydroxy-2-mercaptopyridine complex was prepared by self-assemby reaction of Zn(NO3)2 and 3-hydroxy-2-mercaptopyridine (hmp). Single-crystal X-ray diffraction analysis indicates that it crystallizes in a tet...The zinc 3-hydroxy-2-mercaptopyridine complex was prepared by self-assemby reaction of Zn(NO3)2 and 3-hydroxy-2-mercaptopyridine (hmp). Single-crystal X-ray diffraction analysis indicates that it crystallizes in a tetragonal system, space group (No. 122) with a = 13.4562(6), c = 13.6860(8) , V = 2478.1(2) 3, Z = 8, Mr = 317.67, Dc = 1.703 g/cm3, m(Mo-Ka) = 2.308 mm-1 and F(000) = 1280. R = 0.0289 and wR = 0.0676 for 1040 observed reflections (I > 2s(I)). The crystal structure consists of a neutral molecule with a distorted tetrahedral cis-ZnS2O2 core, in which the mononuclear Zn2+ ion is coordinated by two O and two S atoms from two hmp ligands with the average bond distances of 2.301(1) ?for ZnS and 1.986(3) ?for ZnO. The 1H . NMR and IR spectra of the compound are discussed.展开更多
基金Project(51104185)supported by the National Natural Science Foundation of ChinaProject(2010QZZD003)supported by the Key Project of Central South University of Fundamental Research Funds for the Central Universities of China
文摘为探究溶剂对合成有机金属框架化合物的影响机制,采用实验和DFT理论计算相结合的方法,研究溶剂N,N-二甲基甲酰胺(DMF)和N-甲基-2-吡咯烷酮(NMP)对溶剂热法合成有机金属框架材料[Zn4O(BDC)3]8的影响及溶剂与框架间的微观作用机制。粉末X射线衍射(XRD)和扫描电镜(SEM)结果表明,NMP在[Zn4O(BDC)3]8孔道中的吸附力较DMF的弱,NMP分子更容易从框架中脱除;热重(TG)和热重-红外联用(TGA/FT-IR)结果表明,以DMF为溶剂合成的[Zn4O(BDC)3]8的热分解温度和热稳定性较高;氮气等温吸附实验(BET)发现,以NMP为溶剂合成的[Zn4O(BDC)3]8的气体吸附性能更强,兰缪尔比表面积高于用DMF合成的[Zn4O(BDC)3]8。调控介电常数设定溶剂分别为NMP和DMF,用COSMO溶剂化方法对溶剂分子与框架化合物基本结构单元Zn4O(BDC)3间相互作用模型进行几何优化计算,发现溶剂设定为NMP时Zn4O(BDC)3优化结构的总能量较溶剂设定为DMF时的高8.6405 k J/mol,这说明DMF分子与Zn4O(BDC)3间的结合力强于NMP分子的,溶剂化作用降低了Zn与O间的离子性;用DMol3在GGA-BLYP/DN水平计算了DMF、NMP或DEF溶剂分子在[Zn4O(BDC)3]8晶体孔道中的相互作用,与DMF相比,NMP在孔道中能量状态稳定性较差,在能量状态角度上NMP应最容易从框架材料孔道中脱除。研究结果说明NMP更有利于合成性质良好的[Zn4O(BDC)3]8,与DMF相比NMP与框架结构基元间的作用力较弱。
文摘A novel one-dimensional chain complex [Zn(dafo)2(H2O)2](NO3)2 was synthesized. It has been characterized by IR, UV, TGA, Elemental analysis and X-ray diffraction analysis. The crystal belongs to triclinic system, P1 space group. The Crystallographic data are: a = 0.702 7(14) nm, b = 0.828 95(17) nm, c = 10.225(2) nm, α = 95.02(3)°, β = 91.45(3)°, γ = 99.85(3)°. The crystal structure data indicate that the Zn(Ⅱ) ion was coordinated with the four nitrogen atoms of two dafo and two oxygen atoms of two coordination water molecules, respectively. The complex has a one-dimensional chain structure, which is formed by hydrogen bonds.
文摘A\} novel two-dimensional coordination polymer Zn 3(PTC) 2(H 2O) 8·4H 2O was formed by \{Zn(CH 3COO) 2·\}2H 2O and 2-pyridine-1,3,5-tricarboxylate(H 3PTC) under the hydrothermal condition at 417 K and characterized by fluorescence. The crystal structure of the compound was determined by single-crystal X-ray diffraction analyses. The six-coordinated Zinc(Ⅱ) center displays an octahedral geometry . The crystal is monoclinic and space group is P2(1)/c with a=0.722 70(14) nm, b= 1.866 7(4) nm , \{c=\}1.072 6(3) nm, α=90°, β=103.198(19)°, γ=90°, V=1.408 7(6) nm 3, Z=4, D c= 2.474 Mg/m 3, M r=828.536, μ=3.099 mm -1 , F(000)=1 060, GOF=0.892, R=0.061 3, wR= 0.133 9 .
基金Project supported by the National Natural Science Foundation of China (Grant No 10774145)
文摘Structural phase transitions of Zn4Sb3 and its substitutional compounds （Zn0.98M0.02）4Sb3 （M = Al, Ga and In） are investigated by electrical transport measurement and differential scanning calorimetry below room temperature. The results indicate that both β→α and α→α′ phase transitions of Zn4Sb3 are reversible and exothermic processes, which may be explained as that both the transitions originate from the ordering of the disordered interstitial Zn and vacancies in regular sizes. The derived activation energies of β→α and α→α′ phase transition processes for Zn4Sb3 are E1 = 3.9 eV and E2 = 4.1 eV, respectively. Although no remarkable influence on activation energy E2 is observed after A1 doping, A1 substitution for Zn causes E1 to increase to 4.6 eV, implying its suppression of β←→α transition to a great extent. Moreover, it is found that both β←→α and α←→α′ transitions are completely prohibited by substitution of either In or Ga for Zn in Zn4Sb3. The underlying mechanisms for these phenomena are discussed.
基金the Innovative Project (No. IP01007)the Introduction of Overseas Elitists Program (No. IB990168) of the Chinese Academy of Sciences
文摘The zinc 3-hydroxy-2-mercaptopyridine complex was prepared by self-assemby reaction of Zn(NO3)2 and 3-hydroxy-2-mercaptopyridine (hmp). Single-crystal X-ray diffraction analysis indicates that it crystallizes in a tetragonal system, space group (No. 122) with a = 13.4562(6), c = 13.6860(8) , V = 2478.1(2) 3, Z = 8, Mr = 317.67, Dc = 1.703 g/cm3, m(Mo-Ka) = 2.308 mm-1 and F(000) = 1280. R = 0.0289 and wR = 0.0676 for 1040 observed reflections (I > 2s(I)). The crystal structure consists of a neutral molecule with a distorted tetrahedral cis-ZnS2O2 core, in which the mononuclear Zn2+ ion is coordinated by two O and two S atoms from two hmp ligands with the average bond distances of 2.301(1) ?for ZnS and 1.986(3) ?for ZnO. The 1H . NMR and IR spectra of the compound are discussed.
