Synthesis of monoamine derivatives of [Ir 4(CO) 12]. X-ray crystal structure of [Ir 4(CO) 11(4-picoline)

Abstract

The mono-substituted amine derivatives [Ir 4(CO) 11L] (L = pyridine ( 1), 4-methylpyridine ( 2), 4- ter-butyl pyridine ( 3), 3,5-dimethylpyridine ( 4), 3,4-dimethylpyridine ( 5)) were obtained by the reaction of [Ir 4(CO) 11Br] − with the corresponding aromatic amine. In the solid state, cluster 2 has an approximate C s symmetry with all terminal ligands as shown by an X-ray analysis. In solution, this unbridged structure is in dynamic equilibrium with two other isomeric forms having three edge-bridging CO’s on a common basal face and the amine ligand coordinated in axial or in radial position relative to this face.