β-烷基对卟吩异构化的取代基效应  

SUBSTITUENT EFFECTS OF β-ALKYLS ON THE ISOMERIZATION REACTION OF PORPHINE

作　　者：张宏[1] 黄鸳珍[1] 马思渝[1] 

机构地区：[1]北京师范大学化学系,北京100875

出　　处：《北京师范大学学报（自然科学版）》2002年第5期661-666,共6页Journal of Beijing Normal University(Natural Science)

基　　金：国家自然科学基金资助项目 (2 9992 5 90 - 1)

摘　　要：用 AM1MO方法和过渡状态理论研究了 β-甲基和 β-乙基对卟吩异构化反应的影响 .具体计算了卟吩和这 2个β-烷基卟啉异构化的反应势能剖面 ,以及卟吩反应与它们的反应速率常数的比值 .结果表明 ,β-烷基取代后 ,活化焓因素对异构化反应是不利的 ,而活化熵是一个影响权重更大的因素 .活化熵变化的本质是由The effects of β methyls and β ethyls on the isomerization reaction of porphine are studied by using AM1 MO method and transition state theory.The reaction potential energy profiles and the ratios of the rate constant of porphine isomerization and β alkyl porphyrin ones are calculated in detail. The results show that when the β hydrogen atoms are substituted by alkyls, the active enthalpy factor is unfavorable to the isomerization reaction while the active entropy is more important factor because of the relative configurational disorder caused by the β alkyls.

关 键 词：AM1MMO方法 卟吩 过渡态 异构化 取代基效应 活化熵 β-烷基 

分 类 号：O626.1[理学—有机化学] O621.[理学—化学]