Complexation of metal carbonyl units with [α-PW11O39]7− and [α2-P2W17O61]10−: insights into the chiral “twisted-sandwich” dimeric structures

Abstract

Several polyoxometalate-supported metal carbonyl complexes, K₇Na₃P₂W₂₃O₈₀{Re(CO)₃}₂·38H₂O (1), (C₃H₁₀N)₈Na₂P₂W₂₃O₈₀{Re(CO)₃}₂·10H₂O (1a) and (C₃H₁₀N)₆KNa₃P₂W₂₃O₈₀{Mn(CO)₃}₂·7H₂O (2), have been prepared from the dimerization of the monovacant Keggin [α-PW₁₁O₃₉]⁷⁻ with metal carbonyl complexes [M(CO)₃]⁺ (M = Re, Mn) in acidic aqueous solutions. The resulting “twisted-sandwich” architectures are chiral, but their crystalline solids are racemic. A detailed investigation involving syntheses, crystal structures, and electrochemistry is presented.