The reactions of ruthenium carbonyl and alkyne-carbonyl complexes with nickelocene, [(η-C 5H 5)Ni(CO)] 2 and (η-C 5H 5) 2Ni 2(RC 2R′). Cyrstal structures of two isostructural heterometallic trinuclear clusters, (η-C 5H 5) 2Ni 2Ru(CO) 3(C 2Ph 2) and (η-C 5H 5) 2Ni 2Fe(CO) 3(C 2Ph 2)

Abstract

The reactions of nickelocene, [(η-C 5H 5)Ni(CO)] 2 and (η-C 5H 5) 2Ni 2(RC 2R”) (R = H, R′ = Bu t; R = R′ = Et, Ph) with Ru 3(CO) 12, H 4Ru 4(CO) 12, HRu 3(CO) 9C 2Bu t and HRu 3(CO) 9(C 6H 9) are reported and compared with those of the iron carbonyls and alkyne-carbonyls. Some new products have been identified and characterized by spectroscpic analyses. The isostructural trimetallic (η-C 5H 5) 2Ni 2Fe(CO) 3(C 2Ph 2) (V) and (η-C 5H 5) 2Ni 2Ru(CO) 3(C 2Ph 2) (Va) have been studied by X-ray methods. Crystals of V and Va are monoclinic, space group Cc. Unit cell parameters for V are: a = 9.334(8), b = 26.717(13), c = 9.143(8)Å, β = 95.15(7)°, and for Va: a = 9.201(9), b = 27.076(15), c = 9.303(8) Å, β = 94.94(7)°. Both structures have been solved from diffractometer data by Patterson and Fourier methods and refined by full-matrix least squares to R = 0.049 for V and 0.044 for Va. The complexes consist of a triangular cluster formed by two Ni and one Fe atoms and two Ni and one Ru atoms, respectively. A cyclopentadienyl ligand is η-bonded to each Ni atom and three terminal carbonyls are attached to the unique metal atom. The diphenylacetylene, σ-bonded to the Ni atoms and π-bonded to Fe or Ru atom, lies almost parallel to the NiNi side of the cluster. The clusters are considerably smaller in size than other complexes of comparable structure. The elongation of the acetylenic CC bond is different in the two complexes V and Va, although the alkyne—metal interactions are comparable.