| 手性Salen Fe与2-乙基-4-甲基咪唑的分子识别研究 |
| Study on Molecular Recognition of Chiral Salen Fe With 2-Ethyl-4-Methyl-Imidazole |
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| 摘要: 合成并表征了3个手性主体1 (t-Bu-Salen FeⅢ)、2 (unsym-Salen FeⅢ)和3 (Salen FeⅢ)，将其用于对客体4 (2-乙基-4-甲基咪唑，EMI) 逐级缔合反应的分子识别研究，首次测定了主体与EMI缔合反应逐级缔合常数KⅠ、KⅡ和反应过程热力学参数ΔrG?m、ΔrH?m、ΔrS?m，详细地考察了主客体体系的圆二色(CD)光谱性质。实验表明：缔合常数KⅠ和KⅡ均按K(3)>K(2)>K(1)顺序递减，缔合反应是一放热、熵减过程，配位数的变化在UV-Vis电子吸收光谱和CD光谱上呈现出等吸收点位移，但没有改变缔合物双偶氮螯环的Δ构型。采用分子力学和量子化学相结合的方法，从理论上对实验结果作出了合理的解释。 |
| 关键词: 手性铁(Ⅲ)配合物 2-乙基-4-甲基咪唑 缔合常数 圆二色光谱 分子力学 |
| 基金项目: |
| Abstract: Chiral hosts of 1 (t-Bu-Salen FeⅢ), 2 (unsym-SalenFeⅢ) and 3 (salen FeⅢ) complexes were synthesized and characterized. The molecular recognition behavior of chiral hosts towards EMI (2-Ethyl-4-Methyl-imidazole) was studied. The association constants (KⅠ and KⅡ) and the thermodynamic parameters of host-guest system were measured for the first time, and the circular dichroism spectra properties were discussed in detail. The results show that the association constants (KⅠ or KⅡ)decrease in the orders of K(3) > K(2) > K(1), and the reaction is an exothermic process with decrease in entropy. The isosbestic point shifts towards short wave-length direction in the electronic absorption spectra and CD spectra, and does not cause inversions of the conformation of the chelated ring of host-guest molecular system with coordination number increase. In addition, the results were explained by means of molecular mechanics and quantum chemistry computation. |
| Keywords: chiral iron(Ⅲ) complex 2-ethyl-4-methyl-imidazole association constant circular dichroism spectra molecular mechanics |
| 投稿时间：2004-06-21 修订日期：2004-10-27 |
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| 朱必学,阮文娟,王树军,曹小辉,朱志昂.手性Salen Fe与2-乙基-4-甲基咪唑的分子识别研究[J].无机化学学报,2005,21(2):169-175. |
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