Three tetranuclear heterometallic coordination compounds of the general formula [(CuL)2M(CuL·CH3OH)](ClO4)2 [(M = Mn(for 2), Co(for 3) and Ni(for 4)] were synthesized by the reaction of the precursor CuL·0.5H2O (1) (H2L = 2,3-dioxo-5,6:13,14-dibenzo-7,12-diphenyl-1,4,8,11-tetraazacyclotetradeca-7,12-diene) with M(ClO4)2·6H2O under solvothermal conditions. The compounds were fully characterized by elemental analysis, FTIR, UV–Vis spectroscopy, powder X-ray diffraction, single-crystal X-ray diffraction analysis. In addition, compound 2–4 were studied by magnetic susceptibility measurements. All three heterometallic compounds are isomorphous, and the central ions Mn(II), Co(II) and Ni(II) are connected to three CuL fragments via exo-cis oxamido bridges. Magnetic susceptibility studies of complexes 2–4 indicate the occurrence of antiferromagnetic coupling between the paramagnetic metals. The experimental data have been fitted according to the following Heisenberg Hamiltonian H^=-2JS^M(S^Cu1+S^Cu2+S^Cu3)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hat{H} = - 2J\hat{S}_{{\text{M}}} (\hat{S}_{{{\text{Cu}}1}} + \hat{S}_{{{\text{Cu}}2}} + \hat{S}_{{{\text{Cu}}3}} )$$\end{document}, leading to J = − 15.24 cm−1, gCu = 2.06, gMn = 1.96 for complex 2, J = − 22.58 cm−1, gCu = 2.1, gCo = 2.55 for complex 3, and J = − 108.2 cm−1, gCu = 2.09, gNi = 2.27 for complex 4, respectively.

中文翻译：

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基于草酰胺桥配体的四核异金属配合物 [Cu3M]（M = Mn(II) Co(II) 和 Ni(II)）的合成、结构和磁性

配合物 2-4 的磁化率研究表明顺磁性金属之间发生了反铁磁耦合。实验数据已根据以下海森堡哈密顿量 H^=-2JS^M(S^Cu1+S^Cu2+S^Cu3)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} 拟合\usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hat{H} = - 2J \hat{S}_{{\text{M}}} (\hat{S}_{{{\text{Cu}}1}} + \hat{S}_{{{\text{Cu}} 2}} + \hat{S}_{{{\text{Cu}}3}} )$$\end{document}, 导致 J = − 15.24 cm−1, gCu = 2.06, gMn = 1.96 for complex 2，对于复合物 3，J = - 22.58 cm-1，gCu = 2.1，gCo = 2.55，对于复合物 4，J = - 108.2 cm-1，gCu = 2.09，gNi = 2.27，分别。