新型手性双核Salen Mn的分子识别研究

合成了新型手性双Salen配体1及双核锰配合物2,并进行了表征.用紫外-可见光谱滴定法研究了主体双核Salen Mn（2）与咪唑、吡啶类客体的分子识别行为.结果表明:对咪唑类客体的缔合常数顺序为K(Im) > K(2-MeIm) > K(N-MeIm);对吡啶类客体缔合常数顺序为K(4-MePy) > K(3-MePy)> K(Py).主体与所有客体的配位数均为2.测定了识别过程的热力学函数ΔrHmθ, ΔrSmθ, 发现反应为放热、熵减过程.利用圆二色光谱研究了识别过程的Cotton效应.用分子力学方法研究了主客体的最低能量构象,结合量化计算结果对实验事实做了进一步解释.

Molecular Recognition Property of Novel Dinuclear Chiral Salen Mn Complex

A novel chiral Salen 1 and its dinuclear Salen Mn complex 2 (host) were synthesized and characterized by elemental analysis,1H NMR,FT-IR,UV-Vis, and CD spectra. The molecular recognition of 2 with imidazoles and pydines were studied by method of UV-Vis spectrophotometric titration, and it seems that the binding constants are in the orders of K(Im) > K(2-MeIm) > K(N-MeIm) (imidazoles), K(4-MePy) > K(3-MePy) > K(Py) (pydines). All of them have a coordination number of two. The thermodynamic functions ΔrHmθ,ΔrSmθ were also calculated. The results indicated that the processes were exothermic and entropy decreasing. CD spectra of recognition process were studied and the results were consistent with those of thermodynamics. Moreover, the lowest energy configurations of host-guest were obtained by simulated annealing, and quantum chemical calculation was performed based on these configurations. The experimental phenomena were confirmed by the results of quantum chemical calculation.