A TETRANUCLEAR COBALT COMPLEX WITH MERCAPTOPYRIDINE N-OXIDE AS LIGAND - SYNTHESIS AND CRYSTAL STRUCTURE OF [NA3CO4(MU(3)-O)(2)-(MPO)(8)(DMF)(4)]BR-CENTER-DOT-2DMF (MPO=2-MERCAPTOPYRIDINE-N-OXIDE)

摘要

A new compound [Na3Co4(mu 3-O)(2)(mpo)(8)(DMF)(4)]Br . 2DMF (1) was prepared by reacting CoBr(PPh(3))(3) and Nampo (mpo = 2-mercaptopyridine-N-oxide), and structurally characterized by X-ray diffraction methods. The title compound crystallizes in the triclinic space group with a = 13.393(7), b = 14.00(1), c = 13.029(4) Angstrom, alpha = 92.29(4), beta = 110.56(3), gamma = 115.32(4)degrees, V = 2015(2) Angstrom(3), Z = 1 and R (R(W)) = 0.047 (0.053) for 1820 reflections (I>3 sigma(I)). The complex contains four cobalt atoms in the form of a square plane with indirect metal-metal bonds. Each Co atom is coordinated by two bidentate mpo ligands with StOb-D and StOb-T coordination modes, respectively. Two Co-2(mpo)(4)O groups each bridged by mu(3)-O in the Na3Co4 core are linked by Na-3 through the oxygen atoms of the mpo ligands and the bridging mu(3)-O atoms to form a dumbbell-like structure. The structure of the symmetric tetracobalt cation [Na3Co4(mu(3)-O)(2)(mpo)(8)(DMF)(4)](+) possesses a crystallographic inversion center through the Na(1) atom. The relevance of the spectroscopic and magnetic properties to the structure of 1 is also discussed. [References: 16]