Tetranuclear vanadium(III) carboxylate chemistry, and a new example of a metal butterfly complex exhibiting spin frustration: structure and properties of [V4O2(O2CEt)7(bpy)2](ClO4)

Abstract

Treatment of [VCl₃(thf)₃](thf = tetrahydrofuran) with bpy (bpy = 2,2′-bipyridine) and NaO₂CEt in a 1 : 1 : 3 molar ratio in Me₂CO followed by addition of ClO₄^– allows isolation of [V₄O₂(O₂CEt)₇(bpy)₂](ClO₄)[4(ClO₄)], which contains a butterfly-like V₄ unit; variable-temperature magnetic susceptibility studies show 1 to possess both ferro- and antiferro-magnetic exchange interactions leading to spin-frustration effects and an S= 3 ground state.