The chemistry of polynuclear compounds. Part 31. Synthesis of undecacarbonylhydridotriosmate(1–) and its reaction with octadeca-carbonylhexaosmium to give a carboxylate-bridged anionic enneaosmium species

Abstract

Treatment of [Os₃(CO)₁₂] with KOH in MeOH gives the anion [Os₃H(CO)₁₁]^–; low-temperature ¹³C n.m.r. spectroscopy reveals that the structure of this hydrido-cluster is the same as that established for [Fe₃H(CO)₁₁]^– in the solid state; at higher temperatures, fluxional behaviour similar to that previously observed for [Fe₃H(CO)₁₁]^– occurs. The [Os₃H(CO)₁₁]^– anion reacts with [Os₆(CO)₁₈] to produce the Os₉, anion [(OC)₁₀HOS₃(µ-CO₂)Os₆(CO)₁₇]^– which contains an Os₃, and Os₆ unit linked by a CO₂, group. Carbon- 13 n.m.r. spectroscopic studies reveal that the C atom of the CO₂ linkage arises from the [OS₆(CO)₁₈].