ChemInform Abstract: Structural, Spectroscopic, and Electrochemical Characterization of Tetrakis-μ-(2-pyrrolidinonato)-dirhodium(II) and Tetrakis-μ-(δ-valerolactamato)-dirhodium(II).

ChemInform Abstract

The title complex (I) (ca. 90% yield) and its δ-valerolactam analogue are formed by a ligand-exchange reaction of 2-pyrrolidinone and 2-piperidinone with the acetate groups of tetraacetatodirhodium(II). Oxidation potentials for both the complexes are given. They bind CO rapidly and reversibly in solvents such as MeCN. Formation constants are reported. The complexes (II) (P1, Z=1) and its δ-valerolactam analogue (C2/c, Z=4) are characterized by crystal structure determinations. In both the compounds the axially bound neutral lactam ligands are stabilized by intramolecular hydrogen bonds.