Anomalous behaviour of [Nb(CO)6]– and [Ta(CO)6]– towards protons. Crystal and molecular structure of the organometallic acid [C4H8OH]+[Nb2(CO)8Cl3]–·C4H8O

Abstract

Treatment of [M(CO)₆]^– with HX (X = Cl, AcO) under anhydrpus conditions or in aqueous buffered solution yielded the diamagnetic [M₂(CO)₈X₃]^– anions of d⁴ niobium (I) and tantalum (I); the crystal and molecular structure of the title compound was solved by X-ray diffraction methods, showing that each niobium centre is heptaco-ordinated to four terminal carbonyl groups and to three bridging chlorides.