STRUCTURE AND METAL COORDINATION OF THE DIPHOSPHINE 2,2'-BIS((DIPHENYLPHOSPHINL)METHYL)-1,1'-BINAPHTHYL (NAPHOS)

The crystal structure of the diphosphine 2,2'-bis((diphenylphosphino)methyl)-1,1'-binaphthyl (1, NAPHOS) has been determined by means of an X-ray diffraction study. The compound crystallizes in the triclinic space group P ($) over bar 1 with a = 10.568(1) Angstrom, b = 10.737(1) Angstrom, c = 15.986(1) Angstrom, alpha = 81.63(1)degrees, beta = 86.42(1)degrees, gamma = 81.47(1)degrees, V = 1773 Angstrom(3), and Z = 2. The metal complex Mo(CO)(4)(NAPHOS) (4) crystallizes in the space group P2(1)/c with a = 11.064(3) Angstrom, b = 15.931(2) Angstrom, c = 28.462(8) Angstrom, beta = 100.67(1)degrees, V = 4930 Angstrom(3) and Z = 4. Molecular mechanics (MM) calculations for both Mo(CO)(4)(NAPHOS) (4) and Mo(CO)(4)(BISBI) (5) show an excellent match with the experimentally determined structures. A molecular dynamics (MD) simulation is demonstrated to be an efficient tool to sample over the accessible conformational space in order to cope with the ''global minimum problem''. The dynamic behavior of these compounds in solution is also explainable on this basis.