摘要
采用密度泛函理论结合对称性破损态方法,选用氧桥联稀土钆双核配合物为研究对象,通过与实验值比较,探讨了不同泛函与基组对计算磁耦合常数的影响.结果表明,在B3LYP/TZV水平下(Gd为SARC-TZV),相对论效应采用DHK2方法,计算结果与实验测量值-0.022 5cm^(-1)最接近.不同体系测试结果显示,可在该水平下预测新合成稀土钆双核配合物的磁学性质.Mulliken自旋密度分析可知磁中心Gd以自旋极化为主.键级分析表明,2个磁中心之间的磁耦合作用通过桥联氧原子的超交换作用实现.分子磁轨道分析显示2个磁中心间存在较强的轨道相互作用,其磁轨道主要是由钆原子的4f_z^3,4f_z^2_x轨道和桥联氧原子的2pz轨道组成.
Rare earth gadolinium(Gd)dinuclear complexes with oxygen bridges(Gd—O—Gd)were selected as the research object on the baeis of the density functional theory combined with broken symmetry method.Based on the comparison between the computational and experimental values,the influence of functional and basis set on the calculation of magnetic coupling constant was comprehensively investigated.The results showed that the value of ferromagnetic Jwas in excellent agreement with the experimental value of-0.022 5cm-1 at the level of B3LYP/TZV(Gd as SARC-TZV)and relativistic effect using DHK2 method.Moreover,the test results of different systems indicated that at B3LYP/TZV level we could predict the magnetic properties of the newly synthesized rare earth Gd dinuclear complexes.The results of Mulliken spin density analysis indicated that magnetic center Gd was mainly dominated by spin polarization.The Mayer bond order analysis results showed that the magnetic coupling function between two magnetic centers was implemented by the superexchange function of bridged oxygen.Moreover,the analysis of molecular magnetic orbit demonstrated the existence of relative strong orbital interactions between the two magnetic centers.The magnetic orbit mainly consisted of the 4fz3 and 4fz2 orbits of Gd and the 2p_z orbit of bridged oxygen atom.
作者
罗树常
刘翔宇
张竹霞
孙小媛
郑鹏飞
LUO Shu-chang LIU Xiang-yu ZHANG Zhu-xia SUN Xiao-yuan ZHENG Peng-fei(School of Chemical Engineering,Guizhou University of Engineering Science,Bijie 551700,China College of Chemistry and Chemical Engineering, Ningxia University, Yinchuan 750021, China Research Center of Advanced Materials Science and TechnoLogy, Taiyuan University of Technology,Taiyuan 030024,China)
出处
《分子科学学报》
CSCD
北大核心
2017年第2期120-126,共7页
Journal of Molecular Science
基金
国家自然科学基金资助项目(21463020)
贵州省科技厅
毕节市科技局
贵州工程应用技术学院联合基金资助项目(黔科合LH字[2015]5788号)
贵州省科技厅联合基金项目(黔科合J字LKB[2013]19号)
关键词
DFT-BS
稀土钆双核配合物
磁相互作用
磁耦合常数
DFT-BS
rare earth dinuclear gadolinium complexes
magnetic interaction
magnetic coupling constant