TRIOSMIUM CARBONYL-COMPLEXES CONTAINING BRIDGING LIGANDS DERIVED FROMORTHO-FUNCTIONALIZED ANILINES

The trinuclear carbonyl clusters -3(mu-H)(mu,eta(2)-o-HNC(6)H(2)Me(2)N H(2))(CO)(9)] (1) (o-H(2)NC(6)H(2)Me(2)NH(2) = 1,2-diamino-4,5-dimethy lbenzene), [Os-3(mu-H)(mu,eta(2)-o-OC6H4NH2)(CO)(9)] (2) (o-HOC6H4NH2 = 2-aminophenol) and [Os-3(mu-H)(mu,eta(1)-o-SC6H4NH2)(CO)(10)] (3) (o -HSC6H4NH2 = 2-aminothiophenol) have been prepared by reacting [Os-3(C O)(10)(MeCN)(2)] with the appropriate ortho-functionalized aniline in THF solvent. Compounds 1 and 2 are isostructural, having an Os-Os edge spanned by a hydride ligand and by the amido (1) or alkoxy (2) fragme nt of the monodeprotonated 1,2-diamino-4,5-dimethylbenzene or 2-aminop henol ligands. In both complexes, one of the metal atoms of the bridge d Os-Os edge is also attached to the NH2 group of the organic ligand. The structure of complex 3 is related to those of 1 or 2, in that an O s-Os edge is spanned by a three-electron donor ligand (the thiolate fr agment of monodeprotonated 2-aminothiophenol), but differs in that the NH2 group is uncoordinated. The X-ray structure of compound 3 is also reported. The results are discussed taking into account the hard-soft character of the bridging ligands.