两个镉/锌超分子配合物的合成、晶体结构及理论计算

通过水热法合成了2个新的金属-有机超分子配合物[Cd(cba)2(bix)]_2(1)和[Zn(cba)2(bix)]_2(2)(Hcba=2-氯苯甲酸,bix=1,4-双(咪唑基-1-基)苯),并对其进行了元素分析、红外光谱、热重、荧光光谱、单晶和粉末X射线衍射测定。配合物1和2同构,均为零维结构,并且通过π-π堆积形成了三维超分子结构。此外,还用高斯09程序PBE0/LANL2DZ方法对配合物1进行了自然键轨道(NBO)分析,计算结果表明配位原子与Cd(Ⅱ)离子之间存在着共价作用。     

海藻硫酸多糖抑制草酸钙结石形成的化学模拟

用体外模拟方法研究了从海藻异枝麒麟菜中提取的硫酸多糖(ESPS)对尿结石患者尿液中草酸钙晶体生长的影响. ESPS不但诱导与尿路细胞膜粘附力较弱的二水草酸钙晶体形成, 而且抑制一水草酸钙的生长和聚集, 归因于一水草酸钙的富钙(101)晶面与聚阴离子ESPS之间的静电相互作用. 上述结果表明, ESPS是一种抑制草酸钙结石的潜在绿色药物.     

嗜麦芽寡养单胞菌胞外蛋白酶的化学修饰

分别采用苯甲基磺酰氟(PMSF)、对-氯汞苯甲酸(PCMB)、N-乙咪唑(N-AI)、氯胺-T(Ch-T)、N-溴化琥珀亚胺(NBS)、2-巯基乙醇(2-ME) 6种化学修饰剂处理嗜麦芽寡养单胞菌胞外蛋白酶, 研究酶分子中氨基酸侧链基团与酶活性的关系. 结果表明Ch-T, NBS和2-ME能显著抑制酶活性, 而N-AI, PMSF和PCMB对酶活性的影响不大, 说明蛋氨酸残基、色氨酸残基和二硫键是酶活性的必需基团, 而酪氨酸残基、丝氨酸残基和巯基与酶活性无直接关系. 同时检测了EDTA和金属离子对酶活性的影响. 实验结果证实, EDTA, Mg^2＋, Ca^2＋, Hg^2＋和Cu^2＋能显著影响酶活性, 说明该酶为一种金属蛋白酶.     

Hydrothermal Synthesis and Crystal Structure of a Cobalt(Ⅱ) Polymer with One-dimensional Chain Structure: [ Co(phen) (BDC)(H2O)]n·0.5nH2BDC

A metal-organic coordination polymer [Co(phen)(BDC)(H2O)]n·0.5nH2BDC(H2BDC = terephthalic acid, phen = 1,10-phenanthroline) has been hydrothermally synthesized and structurally characterized by elemental analysis, IR spectrum, TG and single-crystal X-ray diffraction. The complex crystallizes in triclinic, space group P1- with a = 9.771(3), b =10.739(3), c= 11.249(4) (A), α = 75.946(3), β = 65.306(3), γ = 86.073(4)°, V = 1039.6(6)(A)3, C24H17CoN2O7, Mr=504.33, Dc = 1.611 g/cm3, μ(MoKa) = 0.878 mm-1, F(000) = 516, Z = 2, the final R = 0.0547 and wR = 0.1138 for 2916 observed reflections (I＞ 2σ(Ⅰ)). It exhibits a one-dimensional zigzag chain-like structure.     

Hydrothermal Synthesis and Crystal Structure of a Cobalt(Ⅱ) Polymer with One-dimensional Chain Structure: [Co(phen)(BDC)(H_2O)]_n·0.5nH_2BDC

A metal-organic coordination polymer [Co(phen)(BDC)(H2O)]n·0.5nH2BDC (H2BDC = terephthalic acid, phen = 1,10-phenanthroline) has been hydrothermally synthesized and structurally characterized by elemental analysis, IR spectrum, TG and single-crystal X-ray diffraction. The complex crystallizes in triclinic, space group P1 with a = 9.771(3), b =10.739(3), c = 11.249(4) , α = 75.946(3), β = 65.306(3), γ = 86.073(4)o, V = 1039.6(6) 3, C24H17CoN2O7, Mr = 504.33, Dc = 1.611 g/cm3, μ(MoKα) = 0.878 mm-1, F(000) = 516, Z = 2, the final R = 0.0547 and wR = 0.1138 for 2916 observed reflections (I > 2σ(I)). It exhibits a one-dimensional zigzag chain-like structure.     

Hydrothermal Synthesis and Crystal Structure of a New Zero-dimensional Complex: [Zn(H2BPTC)(phen)2]n·3nH2O

A new metal-organic coordination complex [Zn(H2BPTC)(phen)2]n·3nH2O (BPTC =3,3',4,4'-benzophenone tetracarboxylate, phen = 1,10-phenanthroline) 1 has been obtained from hydrothermal reaction and characterized by elemental analysis, IR, TG and single-crystal X-ray diffraction. In compound 1, the zinc cation is hexa-coordinated with two carboxylate oxygen atoms from one H2BPTC ligand and four nitrogen atoms from two different phen ligands, showing a slightly distorted octahedral geometry. Crystal data: C41H30N4O12Zn, Mr = 836.06, monoclinic,P21/c, a = 14.2714(9), b = 16.9386(10), c = 15.0151(9) (A),β = 101.3420(10)°, V= 3558.8(4) (A)3, Dc= 1.560 g/cm3,μ(MoKα) = 0.766 mm-1, F(000) = 1720, Z = 4, R = 0.0439 and wR = 0.1157 for 4123observed reflections with I ＞ 2σ(I).     

Hydrothermal Synthesis, Crystal Structure and Photoluminescent Property of a Metal-organic Coordination Polymer with Supramolecular Structure： [Cd2（dpphen）2（BDC）0.5Cl3]n

A novel metal-organic coordination polymer [Cd2(dpphen)2(BDC)0.5Cl3]n (dpphen = 4,7-diphenyl-1,10-phenanthroline, BDC = terephthalate) 1 has been obtained by using hydrothermal synthesis and characterized by elemental analysis, IR, fluorescence spectrum and single-crystal X-ray diffraction. The complex crystallizes in triclinic, space group P1 with a = 9.981(5), b = 10.436(5), c = 21.104(10) , α = 94.640(7), β = 103.160(7), γ = 92.958(8)o, V = 2127.8(17) 3, C52H34Cd2Cl3N4O2, Mr = 1077.98, Dc = 1.682 g/cm3, μ(MoKα) = 1.237 mm-1, F(000) = 1074, Z = 2, the final R = 0.0314 and wR = 0.0757 for 7358 observed reflections (I > 2σ(I)). Furthermore, compound 1 shows blue photoluminescent property at room temperature.     

Theoretical analysis and numerical simulation of acoustic waves in gas hydrate-bearing sediments

Based on Carcione-Leclaire model,the time-splitting high-order staggered-grid finite-difference algorithm is proposed and constructed for understanding wave propagation mechanisms in gas hydrate-bearing sediments.Three compressional waves and two shear waves,as well as their energy distributions are investigated in detail.In particular,the influences of the friction coefficient between solid grains and gas hydrate and the viscosity of pore fluid on wave propagation are analyzed.The results show that our proposed numerical simulation algorithm proposed in this paper can effectively solve the problem of stiffness in the velocity-stress equations and suppress the grid dispersion,resulting in higher accuracy compared with the result of the Fourier pseudospectral method used by Carcione.The excitation mechanisms of the five wave modes are clearly revealed by the results of simulations.Besides,it is pointed that,the wave diffusion of the second kind of compressional and shear waves is influenced by the friction coefficient between solid grains and gas hydrate,while the diffusion of the third compressional wave is controlled by the fluid viscosity.Finally,two fluid-solid(gas-hydrate formation)models are constructed to study the mode conversion of various waves.The results show that the reflection,transmission,and transformation of various waves occur on the interface,forming a very complicated wave field,and the energy distribution of various converted waves in different phases is different.It is demonstrated from our studies that,the unconventional waves,such as the second and third kinds of compressional waves may be converted into conventional waves on an interface.These propagation mechanisms provide a concrete wave attenuation explanation in inhomogeneous media.     

Hydrothermal Synthesis and Crystal Structure of a Lead(Ⅱ) Polymer with a Two-dimensional Network Structure:[Pb_2(PDB)_2(phen)]_n·nH_2O

A new metal-organic complex [Pb2(PDB)2(phen)]n·nH2O (H2PDB=pyridine-3,4-dicarboxylic acid,phen=1,10-phenanthroline) 1 has been hydrothermally synthesized and structurally characterized by elemental analysis,IR spectrum,TG and single-crystal X-ray diffraction.The compound crystallizes in triclinic,space group P1 with a=7.2472(5),b=10.6966(8),c=16.2376(12),α=98.2960(10),β=91.6430(10),γ=97.4810(10)o,V=1233.53(16)3,C26H16O9N4Pb2,Mr=942.81,Dc=2.538 g/cm3,μ(MoKα)=13.697 mm-1,F(000)=872,Z=2,the final R=0.0247 and wR=0.0654 for 3886 observed reflections (I 2σ(I)).In the crystal structure,the Pb(1) atom is six-coordinated with four carboxylate oxygen atoms from three different PDB ligands and two nitrogen atoms from phen ligand,showing a distorted octahedral geometry;the Pb(2) atom is four-coordinated with four carboxylate oxygen atoms from four different PDB ligands,showing a distorted tetrahedral geometry.It exhibits a three-dimensional supramolecular network structure formed by hydrogen bonds and π-π interactions.     

Synthesis and Crystal Structure of a Copper(Ⅱ) Compound with 4-Hydroxybenzoic Acid and Isonicotinamide:[Cu(4-hba)_2(inta)(H_2O)]·H_2O

A new copper(Ⅱ) compound has been prepared and fully characterized by elemen-tal analysis,IR,TG and single-crystal X-ray diffraction.The compound [Cu(4-hba)2(inta)(H2O)]·H2O (4-hba=4-hydroxybenzoic acid,inta=isonicotinamide) 1 crystallizes in the monoclinic system,space group P21/c with a=7.590(5),b=11.027(5),c=23.761(5),β=102.5740(10)o,V=1974.1(16) 3,Mr=991.84,Z=2,Dc=1.669 g/cm3,F(000)=1020,μ=1.166 mm-1,R=0.0353 and wR=0.0604 for 3166 observed reflections (I 2σ(I)).In compound 1,the copper cation is penta-coordinated with two carboxylate oxygen atoms from two different 4-hba ligands,two oxygen atoms from two coordinated water molecules and one nitrogen atom from inta ligand,showing a slightly distorted square-pyramidal geometry.