作　　者： ; ; ;

机构地区： 肇庆学院化学化工学院

出　　处： 《化学试剂》 2011年第8期693-696,762,共5页

摘　　要： 采用MP2/6-31++G**//B3LYP/6-31++G**方法研究了丝氨酸和甘氨酸水致质子迁移的相对难易,探讨了羟甲基取代效应。得到两个主要结论:1)羟甲基取代甘氨酸中的α-H后,其吸电子效应削弱了迁移质子所在的化学键,导致质子迁移所需的最少水分子数目由2个减少为1个;2)通过比较羟甲基取代前后的质子迁移过程,发现羟甲基效应使反应势垒降低了0.917 kJ/mol,使反应吸热减少了6.766 kJ/mol。 The proton transfer in hydrated fl-hydroxyalanine and glycine was studied to probe into the substitution effect of hydroxymethyl by MP2/6-31 ^＊＊ G ^＊＊//β3LYP/6-31^＊＊＋ G ^＊＊method. Two conclusions were drawn as below, 1 ） the chemical bond containing the α-H has been weakened by hydroxymethyl effection, resulting in the decreasing of the minimum number of water molecular necessary to cause proton transfer from 2 to 1 ;2 ） the reaction potential barrier and the reaction endotherm of the proton transfer were reduced by 0. 917 and 6. 766 kJ/mol,respectively,after the α-H of glyeine being replaced by hydroxymethyl.

关 键 词： 取代基效应 丝氨酸 甘氨酸 质子迁移 量子化学

领　　域： [理学] [理学]