Intermolecular interaction and magnetic coupling mechanism of a mixed-valence CuIICuI tetranuclear complex with iodide bridge

A tetranuclear CuICuII mixed oxidation state complex, [CuII 2(μ-I)2CuI 2(μ-I)2(phenP)2I2] (phenPE: 2-(1H-pyrazol-1-yl)-1,10-phenanthroline), has been prepared and its crystal structure is determined by X-ray crystallography. In the complex, CuII is a distorted square pyramid and CuI is a distorted trigonal planar coordination environment; CuII and CuI are bridged by iodide. It is rare to form a CuII-iodide bond and for CuII and CuI to be bridged by iodide. In the crystal, there is a slipped π–π stacking between adjacent CuII complexes, which resulted in the formation of the 1-D chain along the c axis. The fitting for the variable-temperature magnetic susceptibility data gave magnetic coupling constant 2J = −1.16 cm−1 and it may be ascribed to the intermolecular π–π magnetic coupling pathway.