3-甲基-4-对甲基苯基-5-(2-吡啶)-1,2,4-三唑桥联的双核铜配合物的磁性理论研究

The theoretical studies on the antiferromagnetic dimer copper(Ⅱ)coordination complex with 1,2,4-triazole

采用对称性破损态方法结合密度泛函理论,选用反铁磁双核配合物[Cu2(MMBPT)2Cl4(H2O)2.5](MMBPT=3-甲基-4-对甲基苯基-5-(2-吡啶)-1,2,4-三唑)作为研究对象,通过与实验数据相比较,探讨了不同密度泛函方法与基组对计算铜配合物交换耦合常数的准确度.结果表明,4种混合密度泛函DFT(B3LYP,B3P86,B3PW91和PBE0)的计算结果都能和实验所观察到的值-31cm-1符号一致,但只有B3PW91方法得到的结果和实验结果吻合程度最好,同时采用方法B3PW91方法计算所得的交换耦合常数Jab对基组的依赖性较大.研究表明,2个Cu(Ⅱ)离子之间弱的反铁磁相互作用主要源于单占据分子轨道SOMOs小的能量劈裂.

In the present work,the magnetic properties of antiferromagnetic complex [Cu2（MMBPT）2Cl4（H2O）2.5]has been investigated on the basis of various unrestricted density functional theory（DFT）with the broken symmetry（BS）approach.The computational results of the hybrid density functional theory（B3LYP,B3P86,B3PW91 and PBE0）is well agreement with the negative sign of the experimental value,the result of B3PW91 calculation method is closer to the experimental one.The B3PW91 calculation method has a large dependent on the basis set.To the dinuclear copper coordination complex,B3PW91/LANL2 DZ have a significant improvement in exchange coupling constants with the experimental data.