Reactions of phenylimidotrichlorobis(triphenyl-phosphine)rhenium(V). Reaction with trimethyl-phosphine and reduction of trimethylphosphine complex to phenylamido complexes of rhenium(I, III). The X-ray crystal structures of phenylamido-(dinitrogen)tetrakis(trimethylphosphine)-rhenium(I) and phenylamido(buta-1,3-diene)-tetrakis-(trimethylphosphine)rhenium(I)

Abstract

The interaction of Re(NPh)Cl 3(PPh 3) 2 with PMe 3 gives Re(NPh)Cl 3(PMe 3)(PPh 3) or Re(NPh)Cl 3(PMe 3) 2 depending on conditions. In the presence of excess PMe 3 the phenylimido compounds in tetrahydrofuran are reduced by sodium amalgam giving products whose nature depends on the atmosphere (Ar, N 2, H 2 CO, butadiene) used. The following compounds have been characterised: Re(NHPh)(N 2)(PMe 3) 4, ReH(NHPh)(η′-CH 2PMe 2)(PMe 3) 4, Re(H) 2(NHPh)(PMe 3) 4, Re(NHPh)(CO) 2(PMe 3) 3, Re(NHPh)(CO) 3(PMe 3) 2, Re(NHPh)(η 4-C 4H 6)(PMe 3) 3 and Re(NPh)Cl 2(PMe 3) 3. The structures of Re(NHPh)(N 2)(PMe 3) 4 ( 3) and Re(NHPh)(C 4H 6)(PMe 3) 3, ( 8) have been confirmed by single-crystal X-ray diffraction studies. ( 3) is monoclinic, space group P2 1/ n with a = 9.574(2), b = 19.528(3), c = 14.385(3)Å and β = 99.06(2)°; ( 8) is orthorhombic, space group Pbc2 1, with a = 12.207(2), b = 13.884(2), c = 14.242(2)Å. The structures were solved via the heavy atom method and refined by least squares to R values of 0.065 and 0.062 for 3249 and 2009 observed diffractometer data, respectively. In the dinitrogen complex the N 2 and NHPh ligands adopt a cis configuration with ReN bond lengths of 1.955(13) and 2.200(14)Å, respectively. In the butadiene complex, whose structure is not well defined due to disorder and/or pseudo symmetry correlation effects, the ReN (amido) distance is 2.13(3)Å.