Synthesis of novel trimeric µ-oxo-bridged manganese(IV) complexes: [L3Mn3IV(µ2-O)3(µ3-XO4)]Br3(X = P, As, or VV; L = 1,4,7-triazacyclononane)

Abstract

The reaction of (L₂Mn^III₂(µ-O)(µ-MeCO₂)₂](CIO₄)₂ with Na₂HPO₄, (NH₄)₃VO₄, or Na₂HAsO₄ in aqueous solution (pH ca. 9) in the presence of air yields, upon addition of NaBr, deep red crystals of [L₃Mn^IV₃(µ₂-O)₃(µ₃-XO₄)]Br₃(X = P, As, or V^V; L = 1,4,7-triazacyclononane); characterization of the µ-phosphato complex by X-ray crystallography showed the presence of discrete trimeric cations [L₃Mn^IV₃(µ-O)₃(µ-PO₄)]³⁺ where three Mn^IV centres are in a distorted octahedral fac-N₃O₃ donor set connected by three µ₂-oxo bridges and a µ₃-PO₄ bridge.