Reactions of (eta(5)-C9H7)Rh(eta(2)-(CH4)-H-2)(2) with quinones: molecularstructure of [(eta(5)-C9H7)Rh(2,3,5,6-C6O2(CH3)(4))]

Reactions of (eta(5)-C9H7)Rh(eta(2)-C2H4)(2) (1) with quinones were investi gated. Substitution of the labile ethylene ligands was observed upon additi on of either duroquinone (2,3,5,6-tetramethyl- 1,4-benzoquinone) or 1,4-ben zoquinone to complex 1. The molecular structure of neutral (eta(5)-C9H7)Rh( 2,3,5,6-C6O2(CH3)(4)) (3), determined by X-ray diffraction, shows that the duroquinone ligand lies in a plane nearly parallel to the indenyl group. Th e carbonyl moieties of duroquinone lie in a plane incorporating Rh, C2, and the midpoint between C3a and C7a of the indenyl ring. The slip parameter ( Delta = d(average Rh-C3a,7a) - d(average Rh-C1,3)) was calculated to be 0.1 12(2) Angstrom; whereas a value of ca. 0.05 Angstrom had been obtained prev iously from film data. Values for the hinge angle (HA = angle between norma ls to the least-squares planes defined by C1, C2, C3 and C1, C7a, C3a, C3) and fold angle (FA = angle between normals to the least-squares planes defi ned by C1, C2, C3 and C3a, C4, C5, C7, C7a) are 7.2 degrees and 4.0 degrees , respectively.