SYNTHESES OF MONOOXO-TECHNETIUM(V) AND MONOOXO-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 y ields red-violet rhomboids of [TcOCl(PO)(2)] (1). The isostructural co mplex [ReOCl(PO)(2)] (2) is instead prepared by ligand-exchange reacti ons from the labile [ReOCl4](-) precursor. The structure of 1 consists of monomeric units in which the distorted octahedral coordination geo metry around Tc involves the P,O donor atoms from the two bidentate li gands, the Cl and oxo atoms. Crystal data: orthorhombic, space group P 2(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 refine ment based on 2207 reflections converged at R = 0.041.