BONDING OF MOLECULAR NITROGEN .I. CRYSTAL AND MOLECULAR STRUCTURE OF HYDRIDODINITROGENTRIS(TRIPHENYLPHOSPHINE)COBALT(I)

The crystal and molecular structure of a molecular nitrogen complex of cobalt, hydridodinitrogentris(triphenylphosphine)- cobalt(I), CoH(N2)(P(C6H5)3)3, has been determined from three-dimensional X-ray data collected by counter methods. There are two independent, but chemically equivalent, molecules in the asymmetric unit, and the coordination around each cobalt atom is trigonal bipyramidal, with the three phosphorus atoms in the equatorial plane. The Co-N-N entity is linear with N-N bond lengths of 1.101 (12) and 1.123 (13) Å and Co-N-N angles of 178 (2) and 178 (1)°, respectively. The nitrogen molecule is very similar to the isoelectronic molecule carbon monoxide in its mode of bonding, with multiple bonding between the metal and the nitrogen atom, as shown by the Co-N bond lengths of 1.784 (13) and 1.829 (12) Å. The hydride hydrogen atom was detected from difference Fourier syntheses at Co-H distances of 1.6 (1) A. The Co-P distances vary from 2.167 (4) to 2.208 (4) Å. Crystal data: a = 37.159 (14) Å, b = 11.355 (5) Å, c = 21.779 (8) Å, β = 101.3 (2)°, space group C2h5-P21/c, Z = 8, and Dca|cd = 1.284 g/cm3. The structure was refined by least-squares techniques, using 3312 independent reflections for which F2 > 3σ(F2), and the refinement converged to a conventional R factor (on F) of 6.1%. © 1969, American Chemical Society. All rights reserved.