计算机与应用化学
計算機與應用化學
계산궤여응용화학
COMPUTERS AND APPLIED CHEMISTRY
2013年
7期
805-808
,共4页
取代基效应%丙氨酸%甘氨酸%质子迁移%量子化学
取代基效應%丙氨痠%甘氨痠%質子遷移%量子化學
취대기효응%병안산%감안산%질자천이%양자화학
substituent effect%alanine%glycine%proton transfer%quantum chemistry
采用 MP2/6-31++G**//B3LYP/6-31++G**方法研究了丙氨酸和甘氨酸在水分子作用下质子迁移的相对难易,探讨了甲基取代效应。得到2个主要结论：(1)甲基取代甘氨酸中的α-H后,削弱了迁移质子所在的化学键，有利于质子迁移；(2)通过比较甲基取代前后的质子迁移过程,发现甲基效应使反应能垒降低了3.076 kJ·mol-1,使反应吸热减少了5.221 kJ·mol-1。
採用 MP2/6-31++G**//B3LYP/6-31++G**方法研究瞭丙氨痠和甘氨痠在水分子作用下質子遷移的相對難易,探討瞭甲基取代效應。得到2箇主要結論：(1)甲基取代甘氨痠中的α-H後,削弱瞭遷移質子所在的化學鍵，有利于質子遷移；(2)通過比較甲基取代前後的質子遷移過程,髮現甲基效應使反應能壘降低瞭3.076 kJ·mol-1,使反應吸熱減少瞭5.221 kJ·mol-1。
채용 MP2/6-31++G**//B3LYP/6-31++G**방법연구료병안산화감안산재수분자작용하질자천이적상대난역,탐토료갑기취대효응。득도2개주요결론：(1)갑기취대감안산중적α-H후,삭약료천이질자소재적화학건，유리우질자천이；(2)통과비교갑기취대전후적질자천이과정,발현갑기효응사반응능루강저료3.076 kJ·mol-1,사반응흡열감소료5.221 kJ·mol-1。
Is it difficult or easy for proton transfer in hydrated glycine complexes after theα-H of glycine is replaced by methyl was studied by MP2/6-31++G**//B3LYP/6-31++G**method. Two conclusions were drawn as below, (1) the chemical bond which containing theα-H has been weakened by methyl effection, which is beneficial to proton transfer; (2) by comparing the processes of proton transfer fore and after the methyl replacement, it is found that reaction potential barrier was reduced by 3.076 kJ·mol-1 and reaction endotherm was reduced by 5.221 kJ·mol-1.
