Cationic osmium(II) acetyl complexes bearing pyrazolylmethane ligands: Intramolecular and interionic structure and isolation of an intermediate containing the "Os-I-Ag" moiety

The reaction of the complexes cis,trans-[OsI(Me)(CO)(2)(PMe3)(2)] and fac-[OsI(Me)(CO)(3)(PMe3)] with silver salts (AgX) and bis- and tris(pyrazol-1-yl)methane ligands affords the complexes [Os(COMe)((pz)(2)CH2)(CO)(PMe3)Y](+)[BPh4](-) (Y = PMe3, CO) and [Os(COMe)C(pz)(3)-CH-kappa (2))(CO)(PMe3)Y](+)[BPh4] - (Y = -PMe3, CO) or the solvento complexes cis,trans-[Os(Me)(S)(CO)(2)(PMe3)(2)]X-+(-) depending on the reaction conditions. In the reaction of cis,trans-[OsI(Me)(Co)(2)(PMe3)(2)] with AgX in the presence of (pz)(3)CH, the intermediate complexes [(Me)(Co)(2)(pMe(3))(2)Os(mu -I)Ag(pz)(3)CH)](+)[X](-) (X- = CF3SO3-, BF4-) were isolated. The solution interionic structures of cationic complexes were investigated by H-1 NOESY or F-19{H-1}) HOESY NMR spectra.