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)2CH2)(CO)(PMe3)Y]+[BPh4]- (Y = PMe3, CO) and [Os(COMe)((pz)3CH-κ2)(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)3CH, the intermediate complexes
[(Me)(CO)2(PMe3)2Os(μ-I)Ag((pz)3CH)]+[X]- (X- = CF3SO3-, BF4-) were isolated. The solution
interionic structures of cationic complexes were investigated by 1H NOESY or 19F{1H}
HOESY NMR spectra.