Some reactions of tetracarbonyldihydrido-osmium, octacarbonyldihydridodiosmium, and dodecacarbonyldihydridotriosmium

Abstract

Thereactions of [{Os(CO)₄}_nH₂](n= 2 or 3) with carbontetrahalides yield the corresponding dihalides [{Os(CO)₄}_nX₂](X = Cl or Br). Heating [Os₂X₂(CO)₈](X = Cl or Br) in n-heptane solution affords the hexacarbonyl compounds [Os₂X₂(CO)₆]. The reactions of tin tetrachloride with [{Os(CO)₄}_nH₂](n= 1–3) are reported: for n= 1 or 2, the compounds [{Os(CO)₄}_n H(SnCl₃)](n= 1 or 2) have been isolated. The reaction of [Os₂(CO)₈H₂] with triphenylphosphine yields the compounds [Os₂(CO)₇H₂(PPh₃)], [Os₂(CO)₆H₂(PPh₃)₂], [Os(CO)₄(PPh₃)], and [Os(CO)₃H₂(PPh₃)]. Thermolysis of either [Os₃(CO)₁₂H₂] or [Os₂(CO)₈H₂] gives a mixture of the hydrides [{Os(CO)₄}_nH₂](n= 1–4) as well as [OS₃(CO)₁₀H₂] and [OS₃(CO)₁₂]. Mechanisms are discussed for these thermolyses. Heating an n-heptane solution of [Os(CO)₄H₂] produces a moderate yield of [Os₄(CO)₁₂H₄]. Reactions of [{Os(CO)₄}_nH₂](n= 1–3) with C₂F₄ have been studied, but only in the case of [Os(CO)₄H₂] have products, namely cis- and trans-[Os(C₂F₄H)₂(CO)₄], been isolated. I.r., n.m.r., and mass spectra of the compounds are reported and discussed.