Cr(Ⅲ)-羧基配位状态稳定性的理论研究  

Theoretical study on the stability of coordination state of Cr(Ⅲ) with carboxyl

作　　者：丁伟[1,2] 程潇甫[2] 王伟杰[1,2] 张文华[1] 

机构地区：[1]四川大学制革清洁技术国家工程实验室,四川成都610065 [2]四川大学生物质与皮革工程系,四川成都610065

出　　处：《化学研究与应用》2012年第2期242-248,共7页Chemical Research and Application

基　　金：国家自然科学基金(21076130);国家863计划(2011AA0611)

摘　　要：本文采用模型实验结合密度泛函理论B3LYP方法,研究了单核单齿配位、单核螯合配位、多核单齿配位以及多核双点配位Cr(Ⅲ)的氧化还原稳定性。结果显示,单核单齿配位体系的氧化还原稳定性低于单核螯合配位体系。模型实验与理论预测活性得出的结论一致。在此基础上,计算分析了多核Cr(Ⅲ)离子与羧基形成单齿配位结合和双点单齿配位结合后理论参数的差异。前线轨道能差表明这些配合物中Cr(Ⅲ)的氧化还原稳定性顺序为:单核螯合配位>单核单齿配位>四核双点单齿配位>三核单齿配位>二核单齿配位。研究结果将有益于控制皮革中Cr(Ⅵ)的产生。The stability of Cr（Ⅲ） in different coordination states with carboxyl, such as mononuclear mono-coordination, mononucle- ar chelating coordination, polynuclear mono-coordination, and polynuclear muhi-coordination, was investigated by using both model experiment and density functional theory with the B3LYP functional. The results imply that mononuclear mono-coordinate system（ SF-Cr （Ⅲ）, SF： sodium formate） tends to be more active than mononuclear chelating system （ OA-Cr （Ⅲ）, OA： oxalic acid）, and the result of model experiment is consistent with that of theoretical study. Furthermore,the stability of pelynuclear Cr（Ⅲ） coordina- ted complexes was investigated by conceptual density functional theory descriptors. The results suggest that the order of redox stabil-ity of Cr（Ⅲ） in different coordination states should be：mononuclear chelating coordination〉mononuclear mono-coordination〉tetra- nuclear bi-coordination〉trinuclear mono-coordination〉binuclear mono-coordination. These results are beneficial to avoiding the for- mation of Cr（Ⅵ）in the leather.

关 键 词：Cr(Ⅲ) 稳定性 配合物 Cr(Ⅵ) 

分 类 号：O641.12[理学—物理化学]