Mononuclear η 3-allylosmium hydride complexes and the x-ray crystal structure of the solvento complex [OsH(H 2O)(CO) 2(PPh 3) 2]BF 4 · EtOH

Abstract

The osmium(II) hydride [OsHCl(CO)(PPh 3) 3] reacts with 2-methylallylmagnesium chloride and allylmagnesium chloride to give the air-stable η 3-allylosmium hydride complexes [OsH(CO)(η 3-CH 2CRCH 2)(PPh 3) 2] (R = Me or H). The orientation of the η 3-allyl ligand in these complexes has been established by NOE difference spectra. Treatment of [OsH(CO)(η 3-CH 2CMeCH 2)(PPh 3) 2] with fluoroboric acid in the presence of a ligand L (L = Ph 3P or CO) affords the cationic hydride complexes [OsH(CO)(OH 2)(L)(PPh 3) 2][BF 4]. The crystal structure of [OsH(CO) 2(OH 2)(PPh 3) 2][BF 4] · EtOH has been determined.