MOLECULAR-STRUCTURE OF (ETA-5-C5H5)2(CO)NB(MU-CO)CO(CO)3, A HETEROBIMETALLIC COMPLEX WITH A SEMIBRIDGING CARBONYL

The structure of the product of the reaction of (η5-C5H5)2NbH3 with Co2(CO.)8, (η5-C5H5)2(CO)Nb(μ-CO)Co(CO)3, has been determined by X-ray diffraction techniques. Crystals are orthorhombic, with cell parameters a = 13.821 (6) Å, b = 13.352 (5) Å, c = 16.142 (6) Å, space group Pbca, and Z = 8. The structure was refined to R = 0.048 and Rw = 0.057 for 3924 unique observed reflections. The molecule contains a semibridged carbonyl group between the Nb and Co atoms with parameters Nb-Co = 2.992 (1) Å, Nb-C? = 2.531 (4) Å, CB-Co = 1.792 (4) Å, and Nb-CB-Co = 85.8 (1)°. Spectral studies indicate an isomeric mixture in solution. © 1979, American Chemical Society. All rights reserved.