Synthesis of new complexes of osmium and ruthenium containing the carboxylated group of 18β-glycyrrhetinic acid as ligand. Crystal structure of the complex [Os3(μ-H)(μ-O2CC29H45O2)(CO)10]

The reaction of Os3(CO)10(MeCN)2 with 18β-glycyrrhetinic acid (18β-GA) yielded the complex [Os3(μ-H)(μ-O2CC29H45O2)(CO)10] (1). An X-ray study of the complex indicated that the carboxylated group of 18β-GA is coordinated with the trinuclear cluster and the oleanic organic framework is oriented in exo form with respect to the plane defined by the osmium triangle. By contrast, the reaction of Ru3(CO)12 with 18β-GA yielded a dimeric complex characterized by 1H NMR, FTIR and mass spectroscopy as [Ru2(μ-O2CC29H45O2)2(CO)4(THF)2] (2).