桥链冠醚卟啉胆固醇酯的表观质子化常数

用光度法测得三种桥链冠醚卟啉和二种卟啉胆固醇酯的质子化常数，并用ＨＭＯ法进行了量子化学计算，讨论了取代基的电子效应及空间效应对常数的影响。     

四苯基卟啉蒽醌化合物的质子化热力学

表观质子化常数;电子吸收光谱;PM3;四苯基卟啉蒽醌化合物的质子化热力学     

用光度法测定四苯基卟啉及其衍生物的表观质子化常数

本文用光度法测得九种不同卟啉化合物的质子化常数, 并用HMO和MNDO方法计算了有关分子和分子单元, 理论分析解释了实验结果。     

四吡啶基卟啉质子化结构变化的理论研究

为考察m-吡啶基对质子化卟啉结构的影响,用半经验的AM1MO方法,并进行合理的对称性限制,计算了一类重要的卟啉衍生物---四吡啶基卟啉(TPyPH~2)及其质子化二酸(TP~yPH~4^2^+)的构型。通过结构分析,电荷布居分析和前沿轨道分析,讨论了质子化过程中的构型变化以及这种变化对分子堆积可能带来的影响。     

微量光度滴定法测定咔咯化合物的质子化和去质子化常数

采用微量光度滴定法测定了两种具有不同取代基的新型咔咯化合物,三(4-氯苯基)咔咯(化合物1)和三(2,4-二氯苯基)咔咯(化合物2)在非水溶剂中的质子化和去质子化常数。结果表明:化合物1和化合物2在二氯甲烷中均可以与三氟乙酸反应得到一个质子生成正一价阳离子,其质子化常数(lgKb)分别为4.2和4.0。在甲醇溶液中,化合物1和化合物2与氢氧化钠反应时可以失去一个质子生成负一价阴离子,其去质子化常数(lgKa)分别为3.4和3.5。而在二氯甲烷中与碱反应时,化合物1和化合物2均能够一步失去两个质子生成负二价阴离子,其累积去质子化常数(lgβ2)分别为7.9和11.0。     

分析量子化学研究(Ⅱ)——光度分析新显色剂对甲基偶氮氯膦离解与质子化作用及其机理

对甲基偶氮氯膦(CPApM)作为不对称偶氮氯膦类光度分析显色剂,已应用于稀土氧化物与有关矿石、镍基合金中测定钇的含量,本文以分光光度法测得了CPApM的离解常数及质子化常数,运用HMO法进行半经验量子化学计算,并对其电子结构、离解作用与质子化作用及微观机理作了探讨。     

四吡啶基卟啉质子化结构变化研究 Ⅱ.m - 甲基吡啶基的取代 基效应

卟啉衍生物对嵌入并堆积在DNA螺旋中具有高选择性,为考察m-甲基吡啶取代基对质子化卟啉结构的影响,在m-四吡啶基卟啉研究的基础上,用半经验的AM1MO方法,并进行合理的对称性限制,计算了m-四甲基吡啶卟啉(TmPyPH2^4+)及其质子化二酸(TmPyPH4^6+)的几种可能的构型,结果表明,由于m-甲基吡啶的影响,在质子化过程中结构和键电荷布居有明显变化;前沿分子轨道具有与四吡啶基情形相反的变化趋势,质子化二酸与溶液质子的快速交换作用也变得更困难了。     

四苯基卟啉质子化结构变化的理论研究

用半经验的ＡＭＩ ＭＯ方法,进行合理的对称性限制,计算了一类重要的卟啉衍生物──四苯基卟啉（ＴＰＰＨ_２）及其质子化二酸（ＴＰＰＨ_4~2 ）的构型,并通过结构分析,电荷布居分析和前线轨道分析,讨论了质子化过程中的构型变化以及这种变化对分子堆积可能带来的影响。     

螯合离子交换树脂的本征质子化常数

在25 ℃, 分别在水及乙醇-水混合溶剂中, 用电位滴定法研究了国产的含有胺亚二乙酸功能基的大孔螯合树脂D751的质子化反应. 在对树脂相中各组分的活度系数不作任何假定的前提下, 用外推法从表观质子化常数的对数值与滴定度间的关系, 求得了该树脂的三级本征质子化常数. 本文肯定了表观质子化常数对滴定度的依赖性, 合理地解释了在不同溶剂中树脂的酸碱性的变化.     

四苯基卟啉质子化结构变化的理论研究（Ⅱ）－－五氟苯基及吡咯环上氟的取代基效应

卟啉的衍生物在DNA螺旋中的嵌入并堆积具有高选择性。为考察5，10，15，20－四（五氟苯基）卟啉（TF5PPH2）和2，3，7，8，12，13，17，18－八氟－5，10，15，20－四（五氟苯基）卟啉（F28TPPH2）中F取代基对质子化卟啉结构的影响，在四苯基卟啉研究的基础上，用半经验的AM1 MO方法，并进行合理的对称性限制，计算了TF5PPH2和F28TPPH2及其质子化二酸（TF5PHH4^2 ）和（F28TPPH4^2＋）的几种可能的构型。结果表明，由于F取代基的影响，质子化过程中的结构、键电荷布居和前线分子轨道均有明显的变化，二者的质子化二酸与溶液质子的快速交换作用也都变得更加困难。     

Spectral and Acid–Base Properties of Arylidene Derivatives of Dicyclopentano[b,e]pyridines Serving as Fluorescent pH-Indicators

The bathochromic shifts of absorption and emission bands upon the protonation of dicyclopentano[b,e]pyridines fall in the range of 3500-5500 cm^–1. Both the neutral and protonated forms show high fluorescence quantum yields. The spectral and acid–base properties of these compounds may be varied within a broad range by introducing electron-donor substituents into the aromatic side rings. The protonation constants in the ground and excited states of each of these compounds have similar values as a result of steric hindrance arising upon protonation of the pyridine nitrogen atom.     

中位-取代的八乙基卟啉的质子化常数研究

本文报导用Aronoff法测定的十五种卟啉的质子化常数(K₃和K₄),并讨论了中位取代基(硝基、氯和甲氧基)对常数的影响。     

New approach to IR study of monomer-dimer self-association: 2,2-dimethyl-3-ethyl-3-pentanol in tetrachloroethylene as an example

The dimerization of 2,2-dimethyl-3-ethyl-3-pentanol in tetrachloroethylene in the diluted region has been studied at four temperatures by IR spectroscopy. The aforementioned solute compound is chosen because self-association beyond dimerization is hampered by the steric hindrance generated by the bulky sidechains. The integrated absorbances of the monomer bands were treated based on Eq. (9) to obtain its molar absorptivity and dimerization constant. The same dimerization constant as well as the molar absorptivity of dimer band can be obtained based on Eq. (13) from the data treatment of the integrated absorbances of the dimer band. The disparity between two values of dimerization constant determined by two independent sources offers an opportunity to check the consistency of the determination. The standard enthalpy and entropy of dimerization have also been calculated by means of van't Hoff plot, respectively, from the data of temperature-dependent dimerization constants obtained from the monomer bands and dimer bands.     

非对称氮杂环丙烷的亲核开环反应及其区域选择性

本文系统地总结了各类亲核试剂对非对称氮杂环丙烷(吖丙啶)的亲核开环反应及开环的区域选择性.氮杂环丙烷亲核开环的区域选择性是一种空间效应和电子效应平衡的结果,非芳基和非烯基取代的氮杂环丙烷的亲核开环通常发生在氮杂环丙烷取代少的碳原子上,空间效应起主导作用;而芳基和烯基取代的氮杂环丙烷的亲核开环通常发生在氮杂环丙烷芳甲位和烯丙位的碳原子上,电子效应起主导作用,烯基取代的氮杂环丙烷的亲核开环还可以发生在烯基的β-碳原子上;分子内的亲核开环反应主要受成环时环大小的控制,成环时的倾向是五元环>六元环>七元环.对于亲核试剂,一般的亲核试剂也同时受电子效应和空间效应的影响; 而亲核性强的亲核试剂通常只受空间效应的影响.容易生成稳定自由基的亲核试剂容易发生单电子转移机理的开环反应,生成相当于亲核试剂进攻氮杂环丙烷中取代多的碳原子得到的开环产物.     

TiO2纳米晶电极上半菁衍生物分子设计中空间位阻效应的研究

设计合成了具有不同空间位阻的吡啶盐类和喹啉盐类半菁染料(E)-N-(4—磺酸 根丙基)-4-[2-4（4-N，N-二乙基氨基苯基）乙烯基]吡啶鎓盐（EPS），（E）-N-(4- 磺酸根丁基）-4-[2-(4-N,N-二乙氨基苯基）乙烯基]吡啶鎓盐（EPS4）和（E） -N-（4-磺酸根丁基）-4-[2-（4-N，N-二乙基氨基苯基）喹啉鎓盐（EQS4），研究了它们 的光物理性质，并将它们用作TiO2纳米晶电极的光敏化剂引入光电化学电池中。 研究发现:对于吡啶类半菁染料而言，无论是以三个亚甲基或是以四个亚甲基来连接 吸附基团RSO3^-和发色团时，单个的EPS和EPS4分子的光电响应行为一致．但是由于 以三个亚甲基来连接时，与EPS4相比，染料EPS的空间位阻相对较小，有利于其在 多孔膜上的吸附，最终结果是染料EPS对TiO2纳米晶电极的敏化作用好于EPS4．以喹啉 环为受电子基团的染料EQS4与同样含有四个亚甲基的以吡啶环为受电 子基团的EPS4相比，单个EQS4分子的光电响应行为虽然好于EPS4分子，但由于 EQS4分子间的空间位阻较大，影响了它在多孔电极上的吸附，致使其敏化的太阳能 电池的总光电转换效率有所下降．     

Copper(II) complexes of bis(amino amide) ligands: effect of changes in the amino acid residue

A family of ligands derived from bis(amino amides) containing aliphatic spacers has been prepared, and their protonation and stability constants for the formation of Cu(2+) complexes have been determined potentiometrically. Important differences are associated to both the length of the aliphatic spacer and the nature of the side chains derived from the amino acid. In general, ligands containing aliphatic side chains display higher basicities as well as stability constants with Cu(2+). In the same way, basicities and stability constants tend to increase when decreasing the steric hindrance caused by the corresponding side-chain. FT-IR, UV-vis and ESI-MS were used for analyzing the complex species detected in the speciation diagram. UV-vis studies showed the presence of different coordination environments for the copper(II) complexes. Complexes with different stoichiometries can be formed in some instances. This was clearly highlighted with the help of ESI-MS experiments.     

Neutralization of 1-(Aminoethyl)phosphonic Acid and Protonation of Its Salt Anion. Processing Dilatometric Data with the CPESSP Program

Volume changes resulting from neutralization of 1-(aminoethyl)phosphonic acid and protonation of the anion of its bis(tetraethylammonium) salt were determined by the dilatometric method. Protonation constants, apparent molar volumes of the acid and its ionized forms, and volume changes on neutralization of the acid and protonation of its salt were calculated. The presence of the betaine form of the acid in solutions was detected. The rule of the constancy of the sum of the volume effects of the protonation and neutralization reactions was shown to be valid for conjugate acid-base pairs of dibasic acids.     

Conductance study of the thermodynamics of complexation of amantadine, rimantadine and aminocyclohexane with some macrocyclic compounds in acetonitrile solution

A conductance study concerning the interaction between cationic organic ammonium ions amantadine, rimantadine, and aminocyclohexane with 18-crown-6 (18C6), dicyclohexyl-18-crown-6 (DC18C6) and cryptand C222 in acetonitrile solution has been carried out at different temperatures. The stability constants of the resulting 1:1 cornplexes at various temperatures were determined from the computer fitting of molar conductance-mole ratio data. The enthalpy and entropy of complexation reactions were evaluated from the temperature dependence of the formation constants. The influences of different parameters such as steric hindrance of organic amines and macrocycles, conformations of the free and complexed ligands, and solvent-ligand interaction on the thermodynamic data are discussed.     

碘鎓盐/胺体系基态和激发态的光谱研究

研究了碘鎓盐与胺在基态和激发态的相互作用,观察到它们形成以鎓盐为电子受体和胺为电子给体的基态和激发态电荷转移络合物。测定了二苯基碘鎓盐和三乙胺形成的络合物组成为1:1分子比,其缔合常数和克分子吸收系数分别为2.2×10mol^-1和2.8×10³mol^-1·1·cm^-1。实验结果表明,随着胺的给电性增加,电荷转移络合物的吸收波长红移,胺的空间体积增大,由于空间障碍,电荷转移络合物的克分子吸收系数下降。