摘要
合成并表征了 α,α,α,β-四 -(邻氯乙酰胺基苯基 )卟啉 ( 1 )及其锌 ( )配合物 ( 2 ) .用紫外 -可见光谱法测定了配合物 2与三种典型的咪唑类配体轴向配位反应的缔合常数 ,研究了其作为主体分子对咪唑类客体的分子识别 .结果表明 ,各配体的缔合常数顺序为 :K( N-甲基咪唑 ) >K(咪唑 ) >K( 2 -甲基咪唑 ) .根据量化计算结果 ,讨论了三种咪唑类配体与主体分子配位时的进攻方向 ,咪唑和氮甲基咪唑从锌卟啉具有三个侧链的方向进攻 ,而2 -甲基咪唑则从锌卟啉具有一个侧链的方向进攻 .由轴向配位反应的 Δr Hθm、Δr Sθm 和 Δr Gθm 可以确定该反应是放热、熵减小的焓驱动过程 .实验和计算结果均表明 :配合物
meso tetrakis ( o chloroacetylamidophenyl) porphyrin (1) and its zinc complex (2) were synthesized and characterized by means of spectrophotometer technique, the equilibrium constants of the axial coordination reaction were measured between complex 2 and a serious of imidazoles and the molecular recognition of imidazoles by receptor porphyrin 2 was studied. The results showed that the equilibrium constants decreased in the order of K (N CH 3Im)> K (Im)> K (2 CH 3Im). The thermodynamic parameters Δ r H θ m? Δ r S θ m and Δ r G θ m were investigated by Van't Hoff's equation. The tool of calculation chemistry has been performed to deeply probe this recognition reaction. The zinc complex 2 and its coordination with imidazoles were investigated by molecular mechanics for conformational analysis. The experimental and the calculation results showed that the recognition of imidazoles by receptor porphyrin 2 was the result of electronic effect and space effect.$$$$
出处
《南开大学学报（自然科学版）》
CAS
CSCD
北大核心
2002年第1期93-98,共6页
Acta Scientiarum Naturalium Universitatis Nankaiensis
基金
国家自然科学基金 ( 2 0 1 71 0 2 4 )
教育部留学回国人员科研基金
