Temperature and substituent effects on the dissociation constants of 5-azorhodanine derivatives. Semi-empirical quantum mechanical calculation
作者:Tarek M. El-Gogary、A.A. El-Bindary、Azza S. Hilali
DOI:10.1016/s1386-1425(01)00564-9
日期:2002.2
and differences, among the series of the studied RDs that govern and determine their acidic, basic and co-ordinative properties. The geometries of the studied rhodanine were fully optimized at the level of AMI semi-empirical method. Relative stabilities of the enol/keto isomers have been calculated. Proton affinities and proton detachment energies were computed for the series of rhodanine studied, at
介绍了一些若丹宁衍生物(RD)的电子结构和性能的详细分析。本研究的目的是在控制和确定其酸性,碱性和配位性的一系列研究RD中,查明电子结构的异同。在AMI半经验方法的水平上,对所研究的若丹宁的几何形状进行了完全优化。已计算出烯醇/酮异构体的相对稳定性。在AM1方法的水平上,针对所研究的若丹宁系列,计算了质子亲和力和质子离解能,并与通过电位计确定的质子-配体解离常数进行了比较。零点能量和电子相关性已得到考虑。已经发现pK(H)随着取代基的供电子性质的增加而增加。所得的pK(H)线性Hammett图与Hammett常数sigma值的关系表明了所研究分子的共面性。评估的热力学参数(deltaG,deltaH和deltaS)表明解离过程是非自发的,吸热的和熵不利的。