Dinuclear p-cymeneosmium hydride complexes; the measurement of 187Os chemical shifts using 1H-{187Os} two-dimensional n.m.r. spectroscopy

Abstract

The reaction of [(pc)₂Os₂Cl₄](pc =η⁶-p-cymene, 4-isopropyltoluene) with propan-2-ol gives [(pc)OsCl(µ-H)-(µ-Cl)ClOs(pc)], but only in the presence of a salt (KPF₆); J(¹⁸⁷Os–H) between 60.8 and 83.3 Hz have been measured for this complex and for [(pc)Os(µ-H)(µ-X)(µ-Y)Os(pc)]⁺(X = Y = H; X = H, Y = OAc; and X = OAc, Y = Cl) with the ¹⁸⁷Os chemical shift of [(pc)₂Os₂(µ-H)₃]⁺, {quartet, [J(Os–H)84 Hz ]} at δ–2526 p.p.m. (referenced to OsO₄), as measured by ¹H-{¹⁸⁷Os}-two-dimensional n.m.r. spectroscopy, confirming the structures.