Synthesis and Crystal Structure of a Novel Three-dimensional Cu(II) Compound {[Cu(2,2''-bipy)(C7H4O5S)(H2O)2]·(H2O}n

The title compound, {[Cu(2,2'-bipy)(C7H4O5S)(H2O)2](H2O}n (2,2'-bipy = 2,2'- bipyridine), was synthesized by the hydrothermal reaction of Cu(NO3)2(3H2O, 2,2'-bipyridine and 2-sulphobenzoic acid, and structurally characterized by single-crystal X-ray diffraction analysis. The crystal is of triclinic, space group P with a = 9.21(3), b = 10.17(3), c = 10.77(3) (A), α = 77.017(16), β = 89.80(8), γ = 68.46(7)°, V = 911(5) (A)3, Z = 2, (D/s)max = 0.001, Mr = 473.94, Dc = 1.728 g/cm3, μ(MoKα) = 1.365 mm-1, F(000) = 486, the final R = 0.0246 and wR = 0.0628 for 3809 observed reflections with I > 2σ(I). The mononuclear crystal structure extends into a two-dimensional net- work via hydrogen-bonding interactions and a three-dimensional framework is further formed by means of π-π stacking interactions.     

Synthesis and Crystal Structure of Complex [Pb(qina)2(DMSO)]·H2O

A novel complex [Pb(qina)2(DMSO)]·H2O was synthesized, of which qina- is the quinaldic acid radical and DMSO the dimethyl sulfoxide. Elemental analysis, IR spectra, and X-ray single-crystal diffraction were carried out to determine the composition and crystal structure. This complex belongs to monoclinic system, space group P121/n1, with a = 7.1553(17), b = 17.543(2), c = 17.306(2)(A),β = 91.671(4)°, C22H20N2O6PbS, Mr = 647.65, Z = 4, V= 2171.5(6)(A)3, Dc= 1.981g/cm3,μ = 7.908 mm-1, F(000) = 1248, -9≤h≤6, -23≤k≤ 19, -22≤l≤22, R= 0.0221 and wR =0.0488. Weak coordinate bond is formed between oxygen atom in DMSO and Pb(Ⅱ ). There are also weak interactions, such as π-π interaction, hydrogen bonds and so on, among the complex molecules.     

Synthesis and Crystal Structure of [{Cd(hmbdc)(H2O)3}·2H2O]n

A novel coordination polymer [{Cd(hmbdc)(H2O)3}·2H2O]n (hmbdc=5-hydroxy- isophthalic acid) has been synthesized and characterized by elemental analysis, IR spectra and single-crystal X-ray diffraction. The crystal belongs to monoclinic, space group P21/c, with a=9.599(3), b=18.699(5), c=7.557(2) (A), β= 108.198(4)°, V=1288.6(6) (A)3, Z=4, Mr=382.60, Dc=1.972 g/cm3, F(000)=760, μ=1.740, the final R=0.0555 and wR=0.0995 for 1732 observed reflections with Ⅰ ＞ 2σ(Ⅰ). The structural analysis shows that the intermolecular hydrogen bonds and π-π interactions result in a three-dimensional supramolecular framework.     

以金属硫酸氢盐为催化剂在无溶剂条件下高效合成3,4-二氢嘧啶-2(1H)-酮

以金属硫酸氢盐M(HSO4)n(Ca(HSO4)2,Zn(HSO4)2和过硫酸氢钾制剂oxone○R)为催化剂催化醛、1,3-二羰基化合物和尿素进行缩合反应,在90℃及无溶剂的条件下高收率、一锅法合成了3,4-二氢嘧啶-2(1H)-酮.     

离子液体［bmim］HSO4中合成的苯胺与环氧丙烷共聚物的电催化性能

 采用恒电流电解法,在1-丁基-3-甲基咪唑硫酸氢盐(［bmim］HSO4)离子液体中合成了苯胺与环氧丙烷共聚物(PAN-PPO). 扫描电镜观察表明, PAN-PPO由直径小于80 nm的纳米纤维组成. PAN-PPO对草酸氧化具有较好的电催化活性. 采用电化学原位红外光谱技术对草酸的电催化氧化进行了简单的分析.     

富镧和富铈混合稀土贮氢电极的性能

富镧和富铈混合稀土贮氢电极的性能＊赵东江马松艳（黑龙江省绥化师专化学系绥化市１５２０６１）关键词混合稀土贮氢电极性能中图分类号Ｏ６４６．５４混合稀土贮氢合金具有良好的电化学特性和较低的价格，成为贮氢电极研究的主要对象，已经开发出许多实用的电极材料［１...     

Chiral recognition in aqueous solutions. Preferential configurations of α-aminoacids bearing substituted alkyl chains at 25°C

Calorimetric measurements were carried out at 25°C on binary and ternary aqueous solutions containing L and D forms fo the following -aminoacids: tryptophan, cysteine, methionine, phenylalanine, histidine, threonine, and citrulline, which contain both hydrophilic and hydrophobic domains. Differences were found between the values of the homochiral and heterochiral pairwise enthalpic interaction coefficients for tryptophan, cysteine, and methionine. To the contrary, chiral recognition was not detected for phenylalanine, histidine, citrulline, and threonine. The data were interpreted in terms of a preferential configuration model. Chiral recognition is detected only when the interactions of the side chains in the homo- and heterochiral configurations are different. Chiral recognition disappears when a competition exists between zwitterion-zwitterion interactions and side chain-side chain interactions. In some cases, such as for citrulline, compensation effects can occur due to thermal contributions from different domains which mask chiral recognition.     

Second Dissociation Constants of 4-[N-morpholino]butanesulfonic Acid and N-[2-hydroxyethyl]piperazine-N′-4-butanesulfonic Acid from 5 to 55°C

The values of the second dissociation constant, pK ₂, for the dissociation of the NH⁺ charge center of the zwitterionic buffer compounds 4-(N-morpholino)butanesulfonic acid (MOBS), and N-(2-hydroxyethyl)piperazine-N-4-butanesulfonic acid (HEPBS) have been determined from 5 to 55°C, including, 37°C at intervals of 5°C. The electromotive-force (emf) measurements have been made utilizing hydrogen electrodes and silver–silver chloride electrodes. The value of pK ₂ for MOBS was found to be 7.702 ± 0.0005, and 8.284 ± 0.0004 for HEPBS, at 25°C, respectively. The related thermodynamic quantities, G ^o, H ^o, S ^o, and C _p ^o for the dissociation processes of MOBS and HEPBS have been derived from the temperature coefficients of pK ₂. Both the MOBS and HEPBS buffer materials are useful as primary pH standards for the control of pH 7.3 to 8.6 in the region close to that of physiological fluids.     

A class of interaction-round-a-face models and its equivalence with an ice-type model

A new model (called the Temperley-Lieb interactions model) is introduced, in two-dimensional lattice statistics, on a square lattice . The Temperley-Lieb equivalence of this model to the six-vertex, self-dual Potts, critical hard-hexagons and critical nonintersecting string models is established. A graphical equivalence of this model to the six-vertex model generalizes this equivalence to noncritical cases of the above models. The order parameters of a specialization of this model are studied.