X-RAY CRYSTAL-STRUCTURES OF CIS-BIS(DIPHENYLPHOSPHINAMIDE)TETRACARBONYLMOLYBDENUM(0) AND TRANS-BIS(N-METHYL DIPHENYLPHOSPHINAMIDE)TETRACARBONYLMOLYBDENUM(0)

The X-ray crystal structures of cis-Mo(CO)(4)(Ph(2)PNH(2))(2), I, and trans-Mo(CO)(4)(Ph(2)PNHMe)(2), II, are presented. Complex I crystallizes in the monoclinic space group P2(1)/c (a = 13.433(1), b = 12.2719(8), c = 17.318(2)Angstrom; beta = 109.79(1)degrees; V = 2686.1(8)Angstrom(3); Z = 4). Complex II crystallizes in the triclinic space group P $$($) over bar 1 (a = 6.9986(8), b = 10.328(1), c = 11.241(2)Angstrom, alpha = 107.58(1)degrees, beta = 91.76(1)degrees, gamma = 101.28(1)degrees, V = 756.1(4)Angstrom(3), Z = 1). The molybdenum coordination geometry in each complex is a slightly distorted octahedron. The molybdenum-carbon bond lengths for the carbonyls trans to phosphorus in complex I are shorter than those the carbonyls trans to other carbonyls. The average molybdenum-phosphorus distance in I (2.525(5)Angstrom) is similar to those in other diphenylphosphinamide complexes and longer than the molybdenum-phosphorus distance in II in 2.4585(7)Angstrom). The distance between two nitrogen atoms in cis-Mo(CO)(4)(Ph(2)PNH(2))(2) (3.74(3)Angstrom) is significantly larger than the sum of their van der Waals radii (3.10 Angstrom) indicating that the two nitrogens are not hydrogen bonded.