Christopher E. B. Evans

The photodecomposition product μ-oxalato-1κ2O,O′:2κ2O′′,O′′′-bis{bis[2-(2-pyridyl)phenyl-κ2C,N]iridium(III)}–acetone (1/1.974)

An attempt to grow crystals of [Ir(ppy)2(vacac)], (I), from an acetone-d6 solution formed instead crystals of [(Ir(ppy) 2)2(μ-oxalato)] acetone solvate, (II), [Ir 2C11H8N)4(C2O 4)]·-1.974C3H6O, where ppy is the phenylpyridine anion and vacac is vinylacetylacetonate. Each IrIII ion in (II) is in a pseudooctahedral coordination environment, where the pyridine N atoms are trans to each other and the phenyl C atoms are trans to the O atoms of the oxalate bridging ligand. There are two crystallographically independent dimer molecules, each lying on an inversion centre. It is suggested that the oxalate ligand is formed in a series of steps initiated by the aldol condensation of acetone with vacac.