Crystal and molecular structure of di-µ-chloro-tetrakis-(4-methylpenta-1,3-diene)dirhodium(I)

Abstract

Crystals of the title compound are monoclinic, space groupI2/a with cell dimensions, a= 15·247(12), b= 12·103(11), c= 14·848(14)Å, β= 104·6(1)°, Z= 4. The intensities of 1473 independent reflections above background were collected by counter methods and refined to R 0·043. The dimeric molecule has imposed C₂ symmetry. The environment of each metal atom is approximately square planar, the co-ordination plane being defined by two bridging chlorine atoms and the mid-point of the less substituted CC double bonds of two 1,3-diolefins. The two co-ordination planes intersect at 115·8° and there is a weak Rh ⋯ Rh interaction [3·090(3)Å]. Rh–Cl bond distances are 2·410(3) and 2·402(3)Å. The co-ordinated CC bonds are not symmetric with respect to the co-ordination plane, probably because of steric effects; Rh–C distances are 2·120(9) and 2·161 (9) in ligand (A), and 2·121(11) and 2·165(9)Å in ligand (B).