作者:Bernard Denegri、Olga Kronja
DOI:10.1021/jo701379n
日期:2007.10.1
characterized with a more elongated RO−C bond and more increased RO−C−CO angle in 1LG than in 2LG. Calculated affinities of benzhydryl cation toward methyl and phenyl carbonate anions (ΔΔEaff = 11.7 kcal/mol at the B3LYP/6-311++G(d,p) level and ΔΔEaff = 2.7 kcal/mol at the PCM-B3LYP/6-311++G(d,p) level in methanol, respectively) showed that 1LG is more stabilized than 2LG, which is in accordance with greater
在25℃下,在不同的甲醇/水,乙醇/水和丙酮/水混合物中,将一系列X,Y取代的碳酸苄基苯酯1和X,Y取代的碳酸苄基甲基酯2溶剂化。LFER方程log k = s f(E f + N f),用于推导给定条件下碳酸苯酯(1LG)和碳酸甲酯(2LG)离开基团的特定于核试剂的参数(N f和s f)S N中的溶剂1型反应。动力学测量结果表明,碳酸苯酯的溶剂分解速度比碳酸甲酯快一个数量级。在B3LYP / 6-311G(d,p),B3LYP / 6-311 ++ G(d,p)和MP2(full)/ 6-311 ++ G(d,p)级别上优化1LG和2LG的几何形状揭示了由于负超共轭作用,使碳酸根阴离子中的负电荷离域到所有三个氧原子。碳酸苯二酯(1LG)是一个较好的离去基团(在80%v / v的EtOH中N f = -0.84±0.07)比碳酸二甲酯2LG(N f在80%v / v aq EtOH中为−1