Complexes of phosphine-phenolate ligands with the [Re=O](3+) and [Re(HNNC5H4N)(NNC5H4N)](2+) cores

{Complexes incorporating the [Re=O](3+) core have been synthesised with ligands containing the new methyl substituted phosphine-phenolate PO and PO2 donor sets, (2-hydroxy-5-methylphenyl) diphenylphosphine (H(MePO)) and bis(2-hydroxy-5-methylphenyl) phenylphosphine (H-2(Me2PO2)). The analogous tert-butyl ligands, (5-tert-butyl-2-hydroxyphenyl)diphenylphosphine (H(t-BuPO)) and bis(5-tert-butyl-2-hydroxyphenyl) phenylphosphine (H-2 (t-Bu2PO2)), were also prepared. Reaction of either mer-[ReOCl3 (PPh3)(2)] or [NH4][ReO4] in CH3OH with H(MePO) led to formation of [ReOCl(MePO)(2)] (1) in good yield. Reaction of [NH4][ReO4] with H-2 (Me2PO2) in CH3OH afforded [ReO(Me2PO2)(H(Me2PO2))] (2), also in good yield. X-Ray crystallographic analyses of 1 and 2 demonstrated that both complexes are neutral and octahedral, and contain the oxo moiety. Two complexes have been structurally characterised from the reaction of (o-hydroxyphenyl) diphenylphosphine (HPO) with [Re(Hhypy)(hypyH)Cl-3]: [Re(Hhypy)(hypy)(PO)(HPO)]Cl (3) and [ReCl(Hypy)(hypy)(PO)] (4) (hypy = NNC5H4N