铜(Ⅰ)、银(Ⅰ)氮氧自由基配合物磁构效应的理论研究

THEORETICAL STUDY ON THE MAGNETO-STRUCTURAL CORRELATION FOR Cu (Ⅰ) AND Ag (Ⅰ) IMINO NITROXIDES COMPLEXES

采用密度泛函结合对称性破损(DFT-BS)方法,研究了铜(Ⅰ)、银(Ⅰ)氮氧自由基配合物磁构效应。计算结果表明,在考察改变两个氮氧自由基二面角(θ)而引起磁交换偶合常数(J)的变化时发现,将AgⅠ和CuⅠ配合物中氮氧自由基的正交排列逐渐转为平行排列,最终都实现由铁磁性偶合转变为反铁磁性偶合,但转变的过程并不完全相同。分子轨道和自旋集居数分析都很好解释了计算结果。分析还表明,AgⅠ和CuⅠ两个结构相似的配合物,磁构效应之所以不同,实际上是由它们的磁偶合机理不同所导致。

Based on the combined broken-symmetry density functional approach, magneto-structural correlations of [M 1 （imino nitroxide ）2]（PF6）（ M 1 = Ag 1 and Cu 1 ） are discussed by changing the dihedral angle θbetween two imino nitroxide radical planes. The calculated magnetic coupling constant J indicates that the ferromagnetic coupling between imino nitroxides through diamagnetic metal ions （Ag1and Cu1） transform into antimagnetic coupling as the orthogonal arrangement become into the parallel arrangement, but the magneto-structural correlations difference between two complexes is showed in the transform process. The analysis of foregoing molecular orbit and spin density well explain the magneto-structural correlations, the analysis results also indicate that the magneto-structural correlations difference between two complexes, which have similar structure, is due to theirs different magnetism coupling mechanism in fact.