酚氧/苯甲酸共配Fe^(Ⅲ)Ni^(Ⅱ)双核配合物磁学性质理论研究  

The magnetic properties of theFe^(Ⅲ)Ni^(Ⅱ)complexes with phenoxido/benzoate coligands:a theoretical perspective

作　　者：曾兵 罗树常 石谦 ZENG Bing;LUO Shu-chang;SHI Qian(College of Chemical Engineering,Guizhou University of Engineering Science,Bijie 551700,China)

机构地区：[1]贵州工程应用技术学院化学工程学院,贵州毕节551700

出　　处：《分子科学学报》2021年第3期252-260,共9页Journal of Molecular Science

基　　金：毕节市科技计划联合基金资助项目(毕科联合字G[2019]10号);贵州工程应用技术学院科学研究基金资助项目(院科合字G[2017]007号);毕节市中药材产业化工程研究中心资助项目(黔教合KY字[2018]009号);贵州省化学工程与技术重点支持学科资助项目。

摘　　要：基于DFT-BS方法,在不同泛函和基组下研究酚氧/苯甲酸共配Fe^(Ⅲ)Ni^(Ⅱ)双核配合物[Fe^(Ⅲ)(OBz)(L1)Ni^(Ⅱ)(H_(2)O)(μ-OBz)]+的磁学性质.结果表明,在B3LYP*/def2-TZVP水平下计算的磁耦合常数为0.45 cm^(-1),与实验值0.50 cm^(-1)最吻合,可准确描述其磁学性质.自旋布居分析和分子磁轨道分析显示,顺磁中心Fe^(Ⅲ)和Ni^(Ⅱ)主要为自旋离域机理.顺磁中心Fe^(Ⅲ),Ni^(Ⅱ)与桥联配体间存在强的轨道相互作用,其磁轨道贡献主要来自顺磁中心Fe^(Ⅲ)的3d_(x^(2)-y^(2))轨道/3dz2轨道/3dyz轨道、Ni^(Ⅱ)的3d_(x^(2)-y^(2))轨道/3dz2轨道、苯甲酸的π轨道和酚氧桥联配体O原子的p轨道.磁构关系研究表明,随Fe—O—Ni键角θ的增大,顺磁中心Fe^(Ⅲ)和Ni^(Ⅱ)自旋密度减小,其顺磁中心间的磁耦合常数减小,当Fe—O—Ni键角θ>95.69°时,顺磁中心间的磁相互作用由铁磁性相互作用向反铁磁性相互作用转变.Based on the density functional theory and the broken-symmetry method,the magnetic properties of the phenoxido/benzoate coligands Fe^(Ⅲ)Ni^(Ⅱ)heterometalli complex[Fe^(Ⅲ)(OBz)(L1)Ni^(Ⅱ)(H_(2)O)(μ-OBz)]+were studied under different functional methods(general gradient approximation,HDFT and meta-GGA)and basis sets(SVP,TZV,TZVP,def2-SVP,def2-TZVP and def2-QZVP).The results show that the magnetic coupling constant between the paramagnetic centres Fe^(Ⅲ)and Ni^(Ⅱ)ions is 0.45 cm^(-1) at the B3 LYP*/def2-TZVP level,agreeing with the experimental value of 0.50 cm^(-1).At the B3 LYP*/def2-TZVP level,both the high spin and broken-symmetry states spin densities for the phenoxido-bridged heterodinuclear complex[Fe^(Ⅲ)(OBz)(L1)Ni^(Ⅱ)(H_(2)O)(μ-OBz)]+were calculated.The results display that the paramagnetic centers Fe^(Ⅲ)and Ni^(Ⅱ)are mainly spin delocalization mechanisms.There is a strong orbital interaction between the paramagnetic centers Fe^(Ⅲ)and Ni^(Ⅱ)ions and the bridging ligands.The spin density signs of bridged coordinated atoms O(3)and O(4)are similar to that of the paramagnetic center Fe(Ⅲ)ion,indicating that the Ni(Ⅱ)ion spin delocalization has a considerable effect on the bridged O atom compared to Ni(Ⅱ)spin delocalization.The high spin state molecular magnetic orbital shows that strong orbital interactions exist between paramagnetic centers Fe(1)and Ni(2)with the phenoxido-bridged ligands and the benzoate ion.The main contribution of the molecular magnetic orbits of the complex is derived from the 3d_(x^(2)-y^(2)),3dz2 and 3dyz orbitals of the paramagnetic centres Fe^(Ⅲ)ion,the 3d_(x^(2)-y^(2)) and 3dz2 orbitals of the paramagnetic centres Ni^(Ⅱ)ion,Theπ-typemolecular orbital of the benzoic acid and the p orbitals of the phenoxido bridged ligands oxygen atoms.In order to explore the influence of Fe—O—Ni bond angle(θ)on the magnetic properties of Fe^(Ⅲ)Ni^(Ⅱ)heterometalli complexes with phenoxy/benzoic acid,taking the phenoxy/benzoic acid co-ligands Fe^(Ⅲ)Ni^(Ⅱ)he

关 键 词：FeⅢNiⅡ双核配合物 磁构关系 酚氧桥 磁耦合常数 DFT-BS 

分 类 号：O641[理学—物理化学]