Using the crystal to engineer the molecule: cis-trans-isomer selection in anionic bis(orotate) complexes

Abstract

Two chelating orotate²⁻ ligands have been coordinated to the same metal ion, producing the first dianionic bis-orotate complex, [Ni(orotate)₂(H₂O)₂]²⁻, whose geometric isomer can be selected by enabling or vitiating the formation of non-covalent interactions in the solid in which the product is isolated. This provides an important example of the influence and potential use of non-covalent interactions for isomer selection in the synthesis of coordination compounds, as well as the manner in which such stereochemical selection can be achieved by the appropriate use of counterions.