X-ray crystal structures ofcis-bis(diphenylphosphinamide)tetracarbonylmolybdenum(0) andtrans-bis(N-methyl diphenylphosphinamide)tetracarbonylmolybdenum(0)

Abstract

The X-ray crystal structures ofcis-Mo(CO)4(Ph2PNH2)2,I, andtrans-Mo(CO)4(Ph2PNHMe)2,II, are presented. ComplexI crystallizes in the monoclinic space groupP21/c(a=13.433(1),b=12.2719(8),c=17.318(2)A;β=109.79(1)°;V=2686.1(8)A3;Z=4). ComplexII crystallizes in the triclinic space groupP¯1 (a=6.9986(8),b=10.328(1),c=11.241(2)A,α=107.58(1)°,β=91.76(1)°, γ=101.28(1)°,V=756.1(4)A3,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 complexI are shorter than those the carbonyls trans to other carbonyls. The average molybdenum-phosphorus distance inI (2.525(5)A) is similar to those in other diphenylphosphinamide complexes and longer than the molybdenum-phosphorus distance inII in 2.4585(7)A). The distance between two nitrogen atoms incis Mo(CO)4(Ph2PNH2)2 (3.74(3)A) is significantly larger than the sum of their van der Waals radii (3.10 A) indicating that the two nitrogens are not hydrogen bonded.