[Cu2(O COO C-O-N H-O-CH3)4(DMF2)]·4DMF的EPR谱、磁性与电子结构研究

在室温、77K条件下,对·4DMF(1)簇合物的固态和溶液样品进行了EPR谱的测定,获得三套谱图(Ⅰ、Ⅱ、Ⅲ),其分别归属于簇合物中未配对电子的两种形式:(1)类似于自由的单铜离子的未配对电了(Ⅰ、Ⅱ两套谱).(2)双铜未配对电子偶合成的三重态(Ⅲ套谱). 文中用双铜的三重态自旋哈密顿H_S=βHgS+DS_z²+E(S_x²-S_y²)-(2)/3D公式计算三重态EPR谱的参数. 题目化合物(1)与双铜簇合物·4DMF(2)相比较,在配体结构上稍有不同(前者,甲苯胺中的甲基是连接于苯环的间位;而后者,甲基是连接于苯环的对位),由此引起一些磁性参数:有效磁矩μ_eff、磁交换相互作用参数J、相对的电子自旋浓度ρ和EPR谱的超精细结构(h.f.s)参数都有所不同.

EPR SPECTRA,MAGNETIC PROPERTIES AND ELECTRONIC STRUCTURE OF[Cu2(O COO C-O-N H-O-CH3)4(DMF2)]·4DMF

The EPR spectra of binuclear copper (Ⅱ) cluster ·4DMF (1) in solide and solution at room temperature and 77K have been measured. Three groups of lines are observed. They are attributed to two station of the unpaired elec-tron, in the title compound respectively. One is similar to those of a mononuclcar copper sen which present spectra of groups Ⅰ and Ⅱ, while the spectrum of group Ⅲ manifests itself as a triplet state of two coppers coupling dimer. In this paper, the EPR parameters for the triplet state of dimeric copper are calculated by spin Hamiltonian formula H_S=βHgS+DS_z²+E(S_x²-S_y²)-(2)/3D By comparison of the title compound (1) with ·4DMF (2) it is found that there are some differences in the ligand structure, i. e. the difference in the position of Benzenering connecting to CH₃ (the former, meta whereas the latter, patra), resulting in the differences of magnetic parameters (effect magnetic mo ment, parameter of the magnetic exchange interaction J, relative electron spin concentration ρ and h. f. s. parameters).