手性Salen Fe~Ⅲ配合物与咪唑配体轴配反应热力学  

Thermodynamic Study of Axial Coordination Reaction of Chiral Salen Fe(Ⅲ) with Imidazoles

作　　者：朱必学[1] 阮文娟[1] 朱志昂[1] 

机构地区：[1]南开大学化学系,天津300071

出　　处：《应用化学》2005年第5期465-469,共5页Chinese Journal of Applied Chemistry

基　　金：国家自然科学基金(20171024;20271030);天津市自然科学基金(023604011);教育部留学回国人员科研基金资助项目

摘　　要：用紫外可见光谱滴定方法研究了3种手性SalenFeⅢ配合物与4种咪唑配体在CHCl3中的轴配反应热力学性质,结果表明,不同SalenFeⅢ配合物与同一咪唑配体的轴配位常数按K(sym-SalenFeⅢ)>K(unsym-SalenFeⅢ)>K(t-Bu-SalenFeⅢ)顺序减小;测得的轴配反应热力学参数ΔrHθm、ΔrSθm表明此类反应是放热、熵减小的过程,该反应体系中ΔrHθm与ΔrSθm间存在线性关系,有利的焓变补偿了不利的熵变,焓熵作为一种补偿关系贡献于轴配物的稳定性。轴配体系圆二色光谱考察获得与热力学研究一致的结果。By means of UV-Vis spectrophotomeric technique, the thermodynamic behavior of chiral Salen (iron(Ⅲ)) complexes 1, 2 and 3 with imidazole in CHCl_(3) was studied. The results show that the association (constants) decrease in the order of K(sym-Salen Fe^(Ⅲ))>K(unsym-Salen Fe^(Ⅲ))>K(t-Bu-Salen Fe^(Ⅲ)) for the axial coordination reaction of different Salen iron(Ⅲ) complexes with the same imidazole ligands. The thermodynamic parameters Δ_(r)H~θ_m, Δ_(r)S~θ_m of the axial coordination process were determined, and it was found that the axial coordination reaction is an exothermic and entropy decrease process. The favourable enthalpy change compensates the unfavourable entropy change, and the compensatory enthalpy-entropy relationship (contributes) to the stability of the axial coordinated product. The results obtained from the circular dichroism (spectra) are (consistent) with those from the thermodynamics.

关 键 词：手性SALEN Fe^Ⅲ配合物 热力学 圆二色光谱 

分 类 号：O612[理学—无机化学]