Some mononuclear organoimido complexes of W^VI and W^V have been prepared and the X-ray structures of [WCl₄(NC₆H₄Me-p)(thf)](thf = tetrahydrofuran)(1) and [P(CH₂Ph) Ph₃][WCl₅(NC₆H₄Me-p)](2) determined. In both species the octahedral W^VI centre is strongly bound to the tolylimido group [W[graphic omitted]N 1.711(7) for (1) and 1.709(11)Å for (2)] causing a bending down of the four equatorial W–Cl bonds [W–Cl 2.313(4)–2.349(6)Å] and a lengthening of the trans bond [W–O 2.237(6), W–Cl 2.464(5)Å]. The ¹⁴N and ¹⁵N n.m.r. spectra of the ethylimido compounds [WCl₄(NEt)(thf)] and [P(CH₂Ph)Ph₃][WCl₅(NEt)], and the t-butylimido compound [W(NBu^t)₂(NHBu^t)₂] have been obtained. From reactions of the binuclear bis(organoimido) complexes [{WCl₂(NR)(NR′)(NH₂R′)}₂] with neutral ligands [PMe₃ or 2,2′-bipyridyl (bipy)] the mononuclear bis(organoimido) complexes [WCl₂(NR)(NR′)(PMe₃)₂] and [WCl₂(NR)(NR′)(bipy)] were obtained. The X-ray crystal structure of [WCl₂(NPh)₂(bipy)] has been determined and the distorted octahedral structure comprises cis-phenylimido groups and trans-dichloro ligands with the bipy nitrogens trans to the imido nitrogens. The phenylimido ligands are equivalent with mean W[graphic omitted]N bond lengths of 1.775(14) and 1.782(14)Å and mean W–N–C angles of 165.3(12) and 166.3(12)°.