Syntheses of monooxo-technetium(V) and -rhenium(V) complexes of the (o-hydroxyphenyl)diphenylphosphine ligand (POH). Crystal structure of [TcOCl(PO)(2)]

Reduction-substitution reaction of pertechnetate with (o-hydroxyphenyl)diphenylphosphine (POH) at a strictly controlled metal/ligand ratio yields red-violet rhomboids of [TcOCl(PO)(2)] (1). The isostructural complex [ReOCl(PO)(2)] (2) is instead prepared by ligand-exchange reactions from the labile [ReOCl4](-) precursor. The structure of 1 consists of monomeric units in which the distorted octahedral coordination geometry around Tc involves the P,O donor atoms from the two bidentate ligands, the Cl and oxo atoms. Crystal data: orthorhombic, space group P2(1)2(1)2(1), a=10.183(9), b=14.028(9), c=21.40(1) Angstrom, V=3057(3) Angstrom(3), Z=4, D-calc=1.53 g cm(-3); structure solution and refinement based on 2207 reflections converged at R = 0.041.