化学学报 ›› 2003, Vol. 61 ›› Issue (12): 1969-1975. 上一篇    下一篇

研究论文

新型手性双核Salen锰(III)配合物对咪唑、吡啶类客体的分子识别研究

胡国航;阮文娟;高峰;朱志昂   

  1. 南开大学化学系
  • 发布日期:2003-12-15

Study on Recognition of Imidazoles and Pyridines by Novel Chiral Dinuclear Salen (Mn) Complex

Hu Guohang;Ruan Wenjuan;Gao Feng;Zhu Zhiang   

  1. Department of Chemistry, Nankai University
  • Published:2003-12-15

合成并表征了新型手性双核Salen配体1及其锰(III)配合物2(主体2)。用 紫外-可见光谱滴定法研究了主体2与四种咪唑类、四种吡啶类客体在CHCl_3中的分 子识别行为。实验结果表明:对咪唑客体的缔合常数按K(Im) > K (2 - Melm) > K (N-MeIm) > K (EtMelm)顺序递减;吡啶类顺序为K (PyO) > K (4-PhPyO) > K (DMAP) > K(Py),配位数n值均为2。测定了识别过程的Δ_rH_m,Δ_rS_m, 发现此类反应为放热、熵减小的过程,反应体系中存在焓熵补偿关系。与单核的 Salen锰(III)配合物3(主体3)进行比较,除EtMeIm与3的配位数为1外,其他唑 类客全的配位数均为2。就与客体的缔合能力而言,主体2比3大。用圆二色光谱( CD)研究了主-客体的分子识别行为。

关键词: 双核络合物, 锰络合物, 圆二色光谱, 咪唑 P, 吡啶 P, 紫外分光光度法

Chiral dinuclear Salen ligand 1 and manganese (III) complex 2 (host 2) were synthesized and characterized. By method of UV-vis spectrophotomeric technique, molecular recognition behavior of host 2 for imidazoles and pyridines in CHCI3 was studied. The results show that the equilibrium constants decrease in the orders of K~Θ(Im) > K~ Θ(2-MeIm) > K~Θ(N-MeIm) > K~Θ(EtMeIm) (imidazoles) and K~Θ(PyO) > K~Θ(4-PhPy0) > K~Θ (DMAP) > K~Θ(Py) (pyridines), and the coordination number is 2. The thermodynamic parameters Δ_rH_m~Θ, Δ _S_m~Θ of recognition process were determined and it was found to be an exothermic and entropy decrease process. Compared with mononuclear Salen(Mn) complex 3 (host 3), the coordination numbers of host 3 for Im, 2-MeIm and iV-Melm are all 2, but only 1 for EtMelm. In concern of association capacity, host 2 is stronger than host 3. Circular dichroism spectra of host-guest recognition behavior were also studied.

Key words: DINUCLEAR COMPLEX, MANGANESE COMPLEX, CD, GLYOXALINE P, PYRIDINE P, UV

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