Synthesis and characterization of the cubic coordination cluster [CoIII6CoII2(IBT)12]14- (H3IBT = 4,5-bis(tetrazol-5-yl)imidazole)

A self-assembly reaction between the ditopic ligand 4,5-bis(tetrazol-5-yl)imidazole (H3IBT) and cobalt(II) chloride in basic aqueous medium afforded the mixed-valence molecular species (NBu4)14[CoIII6CoII2(IBT)12]·22H2O (1). X-ray analysis of 1 revealed a cubic arrangement of six trivalent and two divalent cobalt ions, with the latter situated on opposing vertices along the cube diagonal. The cubic coordination cluster was further characterized by cyclic voltammetry, mass spectrometry, and magnetic measurements.