Difunctionalised arene Ru6C cluster compounds with electron-withdrawing groups
Abstract
Thermolysis of [Ru6C(CO)17]1 with dimethyl cyclohexa-1,3-diene-1,4-dicarboxylate [C6H6(CO2Me)2-1,4] in dibutyl ether gave two isomeric cluster compounds [Ru6C(CO)14(η6-C6H4(CO2Me)2-1,4]2 and [Ru6C(CO)14(µ3-η2:η2:η2-{C6H4(CO2Me)2-1,4)]3. The solid-state molecular structures of 2 and 3 have been established by low-temperature single-crystal X-ray diffraction analysis. These constitute the first example of co-ordination isomerism for the Ru6C(CO)14 unit with respect to a specific arene. In 2 the arene is η6 bonded to a single ruthenium atom whereas in 3 the arene is bonded in the µ3 mode to a triangular Ru3 face of the octahedral cluster unit. The solid-state structure of 3 is comprised of two rotamers along with two molecules of dichloromethane solvate. The solid-state architectures of 2 and 3 were also examined. The bifunctionalised arene ligand in 2 and 3 has the potential for further organic chemistry at these sites including possible copolymerisation with primary/secondary diamines.