卟吩质子化过程结构变化的理论研究

用ＡＭ１ＭＯ方法计算了质子化卟吩的构型，并通过结构分析、电荷布局分析和前线轨道分析，讨论了其质子化过程的构型变化及Ｒａｍａｎ光谱变化的原因。     

4－（喹啉－8＇－甲基）－1，4，7，10－四氮杂环十三烷－11，13－二酮的合成及其与Cu（Ⅱ）－bipy形成三元配合物的稳定性研究

本文合成了４－（喹啉８＇－甲基）－１，４，７，１０－四氮杂环十三烷－１１，１３－二酮．测定了该配体和４－（吡啶－２＇－甲基）－１，４，７，１０－四氮杂环十三烷－１１，１３－二酮配体的质子化常数及它们与ＣＵ（Ⅱ）形成的二元配合物，与Ｃｕ（Ⅱ）－ｂｉｐｙ形成的三元配合物的稳定常数．还合成了４－（喹啉－８＇－甲基）－１，４，８，１１－四氮杂环十四烷－１２，１＇４－Ｍ酮配体，测定了该配体的质子化常数及其与Ｃｕ（Ⅱ）形成的二元配合物的稳定常数．讨论并比较了这类带有功能性侧基的二氧四胺大环新型配体在水溶液中与Ｃｕ（Ⅱ）的配位能力、配位方式和相应配合物的空间构型．     

Recent results on hydrogen and hydration in biology studied by neutron macromolecular crystallography

Neutron diffraction provides an experimental method of directly locating hydrogen atoms in proteins, a technique complimentary to ultra-high-resolution [1, 2] X-ray diffraction. Three different types of neutron diffractometers for biological macromolecules have been constructed in Japan, France and the United States, and they have been used to determine the crystal structures of proteins up to resolution limits of 1.5-2.5 A. Results relating to hydrogen positions and hydration patterns in proteins have been obtained from these studies. Examples include the geometrical details of hydrogen bonds, H/D exchange in proteins and oligonucleotides, the role of hydrogen atoms in enzymatic activity and thermostability, and the dynamical behavior of hydration structures, all of which have been extracted from these structural results and reviewed. Other techniques, such as the growth of large single crystals, the preparation of fully deuterated proteins, the use of cryogenic techniques, and a data base of hydrogen and hydration in proteins, will be described.     

葡萄糖酸根质子化反应的热力学性质

用量热滴定法研究了水溶液中葡萄糖酸根的质子化反应，在２９８．１５Ｋ及０．１ｍｏｌ／Ｌ（ＮａＣｌ）离子强度下，得到了该反应的平衡常数Ｋａ和热力学参量△Ｈ、△Ｇ及△Ｓ．     

邻氨基噻唑偶氮类试剂质子化机理的研究

邻氨基噻唑偶氮类试剂［１～３］在不同酸度下呈现不同的颜色,关于其质子化发生的位置以及先后次序至今尚未见文献报道．本文通过量子化学计算,结合分光光度法对这类试剂质子化行为进行了研究．１实验方法１．１吸收光谱测定移取１．０ｍＬ１．０×１０－３ｍｏｌ／ＬＴ...     

Thin films of porphyrinperylene molecular array fabricated by electrophoresis methodology

Porphyrin-perylene dyad molecular arrays are impor-tant building blocks for mimic photosynthetic systems and molecular opto-electronics such as molecular wires, logic gates and molecular switches. In recent years, Wasielewski’s group[1―3] and Bocian and Lindsey’s group[4―7] have systematically investigated the electronic structure, the mechanism of transient photoinduced charge and/or energy transfer in a few representative porphyrin- perylene arrays, the acquired results threw light on th…     

超盐体系下铜铁氰络合物的去除及机理

为解决由于浸出液中铜氰络离子(CuCN2-3,CuCN3-4)和铁氰络离子(FeCN4-6)的存在造成金矿石氰化浸出过程中NaCN和活性炭的消耗量增加的问题,初步探讨了超盐体系下铜、铁氰络离子的存在形式,并对比分析了过氧化氢氧化法、氯氧化法和酸化法对上述络合离子的去除效果.结果表明,3种方法对铜氰络离子的去除率均在99%以上,而对铁氰络离子的去除率分别为73%,62%和55%;同时,对于超盐体系的氰化废水,质子化作用比氧化作用更有利于铜、铁氰络离子的分解和去除.     

N—乙酸取代的四氮杂环十四烷加质子平衡的研究

本文用电位—PH 法测得了5,5,7,12,12,14—六甲基一四氮杂环十叫烷 L~1及其 N-乙酸取代物 L~2和 L~3的加质子常数。发现在大环氮原子α位引入烷基或在氮上引入乙羧基会使配体碱性增强。在水溶液中它们主要似 H_2L 的形式存在。探讨了它们与金属 N~(2+)的配合速率结果表明它们的配合速率有如下关系:L~1》L~2>L~3.     

Effects of protonation and deprotonation on the reactivity of quinolone: A theoretical study

Quinolones are the subject of much research as antibacterial compounds and as a new class of antitumor agents.The protonation(P) and deprotonation(D) sites and conformations of quinolone were investigated.The proton affinity(PA) on each of the possible sites in 4-oxo-1,4-dihydroquinoline has been calculated by the restricted Hartree-Fock(HF) and density functional theory(DFT) methods with the basis set 6-311G**.The O-site of protonation was found to be strongly favored over the N-site for the studied compound in the gas phase.Deprotonation takes place in quinolone by detachment of the N-H and COOH protons.The PA of the simple quinolone molecule was used to characterize quinolone reactivity with DNA binding sites.The relative stabilities of the syn and anti conformations were investigated at the B3LYP/6-311G** level of theory;the syn form was shown to be slightly more stable.Its conformation seems to be intrastabilized by hydrogen-bonds consisting of a hydroxyl proton with the O10 atom as the acceptor.We computed and discussed the charge-density distribution and electrostatic potential to explain the reactivity of quinolone.