SYNTHESIS AND CHARACTERIZATION OF ORGANOIMIDO-RHENIUM(V) AND ORGANOAMIDO-RHENIUM(V) COMPLEXES - CRYSTAL-STRUCTURES OF [RECL2(NC(6)H(4)PPH(2)-2)(HNC(6)H(4)PPH(2)-2)], [RE(8-HNC9H6N)(2)O-(PPH(3))][BPH(4)] AND [RE(NPH)(NC5H3S-2-SIME(3)-3)(2)(PPH(3))]-[BPH(4)]

The reaction of [ReCl3O(PPh(3))(2)] in toluene with 2-diphenylphosphin oaniline yielded the brown rhenium(v) amido/imido-complex [ReCl2(NC(6) H(4)PPh(2)-2) (HNC(6)H(4)PPh(2)-2)] 1. This represents the first examp le of a metal complex where a 2-aminophenylphosphine is fully deproton ated to give an N,P chelated imido-complex. The crystal structure of 1 shows a distorted-octahedral geometry with the imido-nitrogen trans t o chloride whereas the amido-nitrogen is disposed trans to a phosphoru s. The Re-N length of 1.988(4) Angstrom for the amido nitrogen is cons istent with protonation of the nitrogen in the chelated ligand. A Re-N bond length of 1.757(4) Angstrom and a Re-N-C angle of 137.8(3)degree s for the deprotonated imide nitrogen imply substantial multiple bondi ng. The ore-complex [Re(8-HNC9-H6N)(2)O(PPh(3))][BPh(4)] 2 was the une xpected product in the reaction of [ReCl3O(PPh(3))(2)] with 8-aminoqui noline in ethanol. It has a distorted-octahedral; structure with two c helated amide ligands. The two quinoline-ring nitrogens as well as the two amido-nitrogens are arranged in a mutually cis configuration. The oxo and triphenylphosphine ligands occupy the remaining co-ordination sites. Reaction of [ReCl3(NPh)(PPh(3))(2)] in ethanol with the steric ally hindered 3-trimethylsilylpyridine-2-thiol (Htspyt) yielded the gr een rhenium(v) phenylimido-complex [Re(NPh)(PPh(3)) (tspyt)(2)][BPh(4) ] 3. Reaction of the unsubstituted pyridine-2-thiol (Hpyt) with the pa rent imido-complex yielded the analogous complex [Re(NPh)(PPh(3)) (pyt )(2)][BPh(4)] 4. The crystal structure of 3 reveals a distorted-octahe dral configuration of the ligands about the central rhenium atom. The imide-and phosphine ligands are cis with the remaining sites being occ upied by the S,N chelated pyridinethiolate ligands. A Re=N bond length of 1.715(8) Angstrom and a Re-N-C bond angle of 166.0(6)degrees are i ndicative of the imide ligand functioning as a four-electron donor.