钼铁硫簇合物化学

Mo—Fe—S簇合物化学是在固氮酶活性中心铁钼辅基(FeMo—co)的分离和性质研究的直接推动下发展起来的。从做为固氮酶活性中心结构模型的第一个Mo—Fe—S簇合物的出的到现在,虽然才短短几年,世界上许多实验室都在从事这方面的研究,并且已经形成了一个相当活跃的新的生物无机化学研究领域。     

手性配体立体选择性萃取分离扁桃酸对映体

Based on chiral ligand exchange, the distribution behavior of mandelic acid enantiomers in the two-phase system containing copper ion(Ⅱ)(Cu²⁺) and N-n-dedecane-L-hydroxyproline (L), was studied. At different pH, the partition of Cu²⁺ in the two-phase system containing N-n-dedecane-L-hydroxyproline, was investigated. The formation constant of binary cpmplex(Li₂Cu) was obtained by regression. The influence of pH, concentrations of Cu²⁺ and chiral ligand, and solvents on partition coefficients(K) and separation factor(α), was discussed. The experimental results show that Li forms more stable ternary complex with D-mandelic acid than with L- mandelic acid. There is a large influence of pH on K and α. At low pH values (<3.5), formation of binary complexes is thermodynamically unfavourable. K and α are best when pH values are above 3.5 and the molar ratio of chiral ligand to Cu²⁺ is 2∶1. At the same time, solvents influence K and α very much.     

LiCoO2中锂离子固相扩散系数随循环次数的变化

The solid diffusion coefficient of lithium-ion in LiCoO₂ cathode material has been investigated by the capacity intermittent titration technique (CITT) at different voltages and at different charge/discharge cycles. By SEM, XRD and FTIR techniques, the structure of LiCoO₂ was studied before and after charge-discharge cycles, and the relationship between solid diffusion coefficient and crystal structure was further discussed. CITT results show that the value of Li⁺ solid diffusion coefficient of LiCoO₂ is about 10^-12 cm²·s^-1. During the whole charge-discharge cycles, the Li⁺ solid diffusion coefficient decreased within the voltage of 4.0～4.3 V, which is attributed to the change of the structure of LiCoO₂.     

新型除草剂丙酯草醚A环14C均标记合成和鉴定

以U-¹⁴C-对氨基苯甲酸为前体, 通过酯化、缩合、还原和取代四步反应获得了A环¹⁴C均标记的丙酯草醚, 用PHPLC对其进行纯化. 采用HPLC-MS(ESI), MS(EI)和¹H NMR验证了其结构, 通过HPLC(外标法)确定其化学纯度大于98%; HPLC-LSC和TLC-IIA两种方法分析表明, 其放射化学纯度大于98%, 其比活度为1.089±0.011 mCi/mmol. 合成的化学收率和放化收率均为53%.     

淀粉制备高吸水性材料

以木薯淀粉为原料,经常温碱糊化,在酸性介质中用KMnO_4为引发剂,进行丙烯腈与淀粉的接枝共聚。结果表明:单体转化率高,接枝效率达95％,支链分子量达30万。接枝共聚物在碱溶液中水解,水解产物的吸水能力超过自重的2000倍。此法通过了中试。     

新颖的二维超分子化合物[CoⅢ(aea)(2,2''''-bipy)]Cl·H2O的水热合成及结构表征

0IntroductionInrecentyearsgreatattentionhasbeenpaidtosupramolecularchemistryandawidevarietyofnet鄄workshavealreadybeenconstructedbasedupontheprincipleofcrystalengineering[1~3].Usually,variousmultifunctionalorganicligands,bothrigidandflexiblemulticarboxyli…     

低热固相反应的反应机理研究(1)--冷融熔机理和冷溶熔机理的模型

本文提出了低热固相反应的冷融熔机理和冷溶熔机理,其中冷融熔机理主要针对于不含结晶水的反应体系,冷溶熔机理主要针对于含结晶水的反应体系,并对低热固相反应动力学提出冷融熔/冷溶熔、扩散、反应、成核、生长的五步机理.两种机理都避开了分子在固相晶格中的扩散,从而对低热固相反应的扩散问题进行了有效的解释,并给出了低热固相反应的热力学和动力学判据.     

3-(3′-吡啶基)-6-芳基-1，2，4-三唑并[3，4-b]-1，3，4-噻二唑衍生物基态和激发态性质

用密度泛函B3LYP方法对3-(3'-吡啶基)-6-芳基-1,2,4-三唑并[3,4-b]-1,3,4-噻二唑衍生物(芳基为苯基、3-吡啶基和苯乙烯基)进行基态几何构型全优化,计算分子的电离势I_p和电子亲和势E_A等相关能量,并用Zerner间略微分重叠(ZINDO)和含时密度泛函(TDDFT)方法计算吸收光谱,用单组态相互作用方法(CIS)优化三种化合物分子的S_1激发态结构,分析其能量与发射光谱的关系,计算溶剂中分子的吸收和发射光谱,并与实验结果对照.计算结果表明,从3-(3'-吡啶基)-6-苯基-1,2,4-三唑并[3,4-b]-1,3,4-噻二唑分子(化合物A)到3-(3'-吡啶基)-6-(3'-吡啶基)-1,2,4-三唑并[3,4-b]-1,3,4-噻二唑分子(化合物B)以及3-(3'-吡啶基)-6-对乙烯苯基-1,2,4-三唑并[3,4-b]- 1,3,4-噻二唑分子(化合物C)的电子亲和势依次增大,愈来愈容易接受电子,吸收光谱和发射光谱红移.     

几个金属卤素簇的合成与性能研究

The hydrothermal reaction of CuBr2 and CuBr with phen·H2O （phen= 1,10-phenanthroline） in a molar ratio of 1：1：1.5 gave birth to the first copper-halo cationic cluster [Cu2^Ⅱ Cu2^Br4 （phen）4 ] ^2＋（1） with tetranuclear anionic cluster [Cu4Br6]^2-. Changing the precursors or their molar ratios, two mononuclear complexes [Cu（phen）2Br]Br·H2O （2） and [Ni（phen）3][CuCl2]2 （3） as well as two unusual copper-halo chains found in polymers [Cu2Br2（phen）]∞ （4） and [Cu^ⅡCu3^ⅠBr2Ⅰ3 （phen）2 ]∞ （5） were obtained. The （Cu2Br2）∞ chain of 4 looks like a linearar ray of hexagons based on fused Cu3Br3 units, and the linear （Cu3Ⅰ3Br^-）∞ chain of 5 is an alternate combination of the rhombic Cu2I2 cores and the Cu4I4Br2^2- units. In addition, the hydrothermal reaction of CuBr2 with NA（NA=nicotinic acid） or INA （INA =isonicotinic acid） resulted in the syntheses of two compounds [CuBr（NA）] （6） and [CuBr（INA）]∞（7） containing staircase chain. Among them the third-order non-linear optical properties of 2, 5, 6 and 7 were investigated and all exhibit the reverse saturable absorption （α2〉0） and self-defocusing performance （n2〈0）.