Determination of N−NO Bond Dissociation Energies of <i>N</i>-Methyl-<i>N</i>-nitrosobenzenesulfonamides in Acetonitrile and Application in the Mechanism Analyses on NO Transfer
作者:Xiao-Qing Zhu、Wei-Fang Hao、Hui Tang、Chun-Hua Wang、Jin-Pei Cheng
DOI:10.1021/ja0443676
日期:2005.3.1
heterolytic and homolytic N-NO bond dissociation energies of G-MNBS in acetonitrile solution cover the ranges from 44.3 to 49.5 and from 33.0 to 34.9 kcal/mol for the neutral G-MNBS, respectively, which indicates that N-methyl-N-nitrosobenzenesulfonamides are much easier to release a NO radical (NO(*)) than to release a NO cation (NO(+)). The estimation of the heterolytic and homolytic (N-NO)(-)(*) bond dissociation
七种取代的 N-甲基-N-亚硝基苯磺酰胺(简称 G-MNBS,G = p-OCH(3), p-CH(3), pH, p-Cl, p -Br, 2,5-2Cl, m-NO(2)) 在乙腈溶液中首次使用滴定量热法和相对热力学循环根据赫斯定律进行评估。结果表明,G-MNBS 在乙腈溶液中的异裂和均裂 N-NO 键解离能的能量标度分别涵盖了中性 G-MNBS 的 44.3 至 49.5 和 33.0 至 34.9 kcal/mol 的范围,其中表明 N-甲基-N-亚硝基苯磺酰胺比释放 NO 阳离子 (NO(+)) 更容易释放 NO 自由基 (NO(*))。乙腈溶液中七个 G-MNBS 自由基阴离子的异裂和均裂 (N-NO)(-)(*) 键解离能的估计给出了 -15.8 至 -12.9 和 -3.1 至 1.8 kcal/mol 的能量范围对于 (N-NO)(-)(*) 键均裂和异裂,这意味着 G-MNBS