A NEW-TYPE OF IMINOPHOSPHINE LIGAND FROM INTERACTION OF LI(2)M(NBU(T))(4), M=W, MO AND PX(3), X=CL, BR - CRYSTAL-STRUCTURES OF W(NBU(T))BR-2[P-2(NBU(T))(3)] AND W(NBU(T))CL(SC6F5)[P-2(NBU(T))(3)]

The interaction of Li(2)M(NBu(t))(4) (M = W, Mo) and PX(3) (X = Cl, Br) produces yellow crystalline compounds of stoichiometry M(NBu(t))X(2)[P-2(NBu(t))(3)], M = W, X = Cl (1a), Br (1b), M = Mo, X = Cl (2). The interaction of W(NBu(t))Cl-2[P-2(NBu(t))(3)] (1a) with TlSC6F5 gives a mono-substituted product (3) but TlOC6F5 produces a disubstituted compound (4). The X-ray crystal structures of 1b and 3 have been determined. In both cases the iminophosphine ligand is tridentate with W-NBu(t) linkages and the geometry is octahedral.