Hemilabile orthometallated acetals: Synthesis, spectroscopic characterization and crystal and molecular structures of [RuCl{η2-C,O-C6H4-2-CH(O2C2H4)}(CO)(PPh3)2] and [HgBr{η2-C,O-C6H4-2-CH(O2C2H4)}]

The cyclometallated acetal-containing complexes [RuCl{η2-C,O-C6H4-2-CH(O2C2H4)}(CO)(PPh3)2] (X = F, Cl, Br, I) have been prepared. The solid state structure (X = Cl) shows four independent molecules which consist of an enantiomeric (planar oxygen) and diasteromeric pair (pyramidal oxygen). Theoretical calculations suggest that ether ligands should be planar unlike thioether ligands which are pyramidal. The electrostatic potential for simplified model compounds suggests this is due to the nature of the lone pairs at oxygen and sulfur respectively.