论文部分内容阅读
密度泛函理论(DFT)结合对称性破损(BS)方法(DFT-BS)研究了两个自由基NITR(Nitronyl Nitroxide)分别以顺式和反式构型与过渡金属Mn(II)形成的八面体配位化合物的磁学性质,计算了Mn(II)-(NITR)2体系磁耦合参数J对以下三个结构参数的依赖关系:(1)Mn-O-N(NITR)键角θ;(2)旋转角ψ(定义为NITR自由基平面围绕Mn-O(NITR)键旋转的角度);(3)Mn-O(NITR)键长.结果表明,与相应的Cu(II)-(NITR)配合物不同,Mn(II)-(NIRT)2配合物的顺式与反式构型都表现了强的反铁磁耦合作用,与变温磁化率实验测定相一致.从分子轨道理论分析,体系的磁交换作用是通过σ-和π-型两种直接交换通道传递的.对于这两种构型,当固定键角θ和键长R,同时变化旋转角ψ时,磁耦合常数J与局域磁轨道的重叠积分平方2abS之间存在着线性关系.
Density functional theory (DFT) combined with symmetric damage (BS) method (DFT-BS) was used to study the interaction of two free radicals NITR (Nitronyl Nitroxide) with transition metal Mn The dependence of the magnetic coupling parameter J of Mn (II) - (NITR) 2 system on the following three structural parameters was calculated: (1) the bond angle θ of Mn-ON (NITR) ) Angle of rotation ψ (defined as the rotation of the NITR radical plane around the Mn-O (NITR) bond); (3) the bond length of Mn-O (NITR) The complex of Mn (II) - (NIRT) 2 showed strong antiferromagnetic coupling between the cis and trans configuration, which was in good agreement with the experimental determination of temperature-dependent susceptibility.From the molecular orbital theory, Of the magnetic exchange through σ- and π-type two direct exchange channels for the two configurations, when the fixed key angle θ and bond length R, while changing the rotation angle ψ, the magnetic coupling constant J and the Bureau There is a linear relationship between the overlapping integral square of magnetic track 2abS.