Experimental and theoretical studies of substituent effects in hydrogen bond based molecular recognition of a zwitterion by substituted arylureas
作者:Craig S. Wilcox、Eun-il Kim、David Romano、Lung Huang Kuo、Arthur L. Burt、Dennis P. Curran
DOI:10.1016/0040-4020(94)00921-g
日期:1995.1
Electron withdrawing groups have a strong effect on hydrogen bonding to aryl ureas. The effect of para substituents modestly exceeds the effect of meta substituents. Among common substituent parameters, σ− (ϱ = 1.77, r2 = 0.988) is found to be the best predictor for the observed effects of para substituents in aryl ureas. Semi-empirical and ab initio methods are used to calculate charge distributions
吸电子基团对氢键合到芳基脲上有很强的作用。对取代基的作用适度超过间取代基的作用。中常见的取代基的参数,σ - (ρ = 1.77,[R 2 = 0.988)被发现是用于对位的取代基在芳基脲所观察到的影响的最佳指标。使用半经验和从头算的方法来计算取代苯衍生物和这些脲中的电荷分布。实验值与预测值的比较(AM1,STO3G,321-G ∗,631-G ∗∗)给出了苯衍生物的偶极矩。结果表明,计算出的这些硫脲的表面电势成功地预测了相对的氢键缔合能。