Synthesis and crystal structure of (η-C5H5)2Ru2Ni(CO)3(μ3CO)(C2Ph2). Facile, one step synthesis of a chiral complex

Abstract

Abstract The complex (η-C 5 H 5 ) 2 Ru 2 Ni(CO) 3 (μ 3 -CO)(C 2 Ph 2 ) has been obtained by refluxing (η-C 5 H 5 ) 2 Ni 2 (C 2 Rh 2 ) and Ru 3 (CO) 12 in hydrocarbons. The structure of the complex has been determined by X-ray methods. Crystals are monoclinic, space group P 2 1 / n , with Z  4 in a unit cell of dimensions a 12.737(7), b 12.228(10), c 15.975(9) A, β 97.53(6)°. The structure has been solved from diffractometer data by Patterson and Fourier methods and refined by full-matrix least-squares to R  2.9% for 3449 independent observed reflections. The complex consists of an isosceles triangle of two Ru and one Ni atoms (Ru(1)−Ru(2) 2.712(3), Ru(1)−Ni 2.550(3) and Ru(2)−Ni 2.553(2) A) bonded to four carbonyls (three are terminal and attached to one Ru atom, while the other asymmetrically triply bridges all three metals), to two cyclopentadienyl ligands (through one Ru and one Ni atom) and to one diphenylacetylene molecule. The alkyne, σ-bonded to one Ru and one Ni atom and π-bonded to the other Ru atom, lies nearly parallel to one Ni−Ru side of the cluster. The presence of the cyclopentadienyl ligand bonded to the Ru atom demonstrates cyclopentadienyl exchange in the reaction. The carbon atom of the triply bridging carbonyl, which is surrounded by four different or differently-substituted atoms, makes the complex chiral. An isomer with a doubly bridging carbonyl was detected in solution and subsequently isolated.