罗树常,刘翔宇,孙小媛.化学通报,2019,82(9):842-848.
吡唑/草酸根混合配位的非对称双核铜配合物磁性的理论研究
Theoretical study on the magnetic properties of asymmetric dicopper(II) complexes with mixed pyrazole/oxalato ligands
投稿时间:2019-04-02  修订日期:2019-05-10
DOI:
中文关键词:  草酸根  磁构关系  DFT-BS  双核铜配合物  吡唑
英文关键词:Oxalato  Magneto-structural correlations  DFT-BS  Dinuclear copper(II) complexes  Pyrazole
基金项目:国家自然科学基金项目(21463020)
作者单位E-mail
罗树常 贵州工程应用技术学院 lsc840927@126.com 
刘翔宇 宁夏大学  
孙小媛 贵州工程应用技术学院  
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中文摘要:
      基于密度泛函理论结合对称性破损态方法,选择不同的泛函方法和基组,研究吡唑/草酸根混合配位的非对称双核铜配合物的磁学性质。结果表明,在B3LYP/def2-TZVP水平计算的磁耦合常数为-127.24 cm-1,与实验值-129 cm-1很吻合,可准确描述吡唑/草酸根混合配位的非对称双核铜配合物的磁学性质。磁轨道和自旋布居分析表明,顺磁中心Cu(II)与桥联配体草酸根离子间存在较强的轨道相互作用,其磁轨道主要由顺磁中心Cu(II)的3dx2-y2轨道、桥联配体草酸根离子的pi键组成,顺磁中心Cu(II)主要是自旋离域机理。配合物磁性与结构关系的研究表明,随着结构参数τ的增加,顺磁中心HS态和BS态自旋密度的平方差和自然磁轨道间重叠积分的平方随之增大,反铁磁性相互作用的贡献增大,配合物磁耦合常数J值减小。
英文摘要:
      The magnetic properties of the asymmetric dicopper(II) complexes with mixed pyrazole/oxalato ligands were studied using DFT-BS by several DFT methods and basis sets. The calculated magnetic coupling constant Jcalc -127.24 cm-1 is in agreement with the experimental parameter -129 cm-1 under the B3LYP/def2-TZVP level, which can accurately describe the magnetic properties of the title complexes. The analyses of magnetic orbitals and the spin density demonstrate that the spin delocalization is originated from Cu(II) ion. Magnetic orbitals are mainly composed of 3dx2-y2 orbitals of Cu(II) ions and pi molcular orbital of the oxalato ion. As the structural parameter τ increasing, the square deviations of the HS and BS state spin densities of the paramagnetic center, as well as the square of the overlap integrals between the natural magnetic orbitals are simultaneously ascended. As a result, the contribution of antiferromagnetic interaction is increased, whereas the magnitudes of the magnetic coupling constants are decreased.
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