Heteroleptic Zinc Catecholate Complexes with N-Donor Ligands

New heteroleptic zinc catecholate complexes based on 3,6-di- tert -butyl- o -benzoquinone and containing metal-coordinated N-donor ligands (2,2'-bipyridine and phenanthroline) were prepared by ligand exchange. According to X-ray diffraction data, both complexes were dimers with multiple intermolecular π–π interactions between the aromatic moieties of neighboring molecules (CCDC nos. 2222704 ( I ), 2222705 ( II )). The electronic transmission spectra of crystalline samples of I and II and their solutions show broad absorption bands in the visible region with a maximum at about 500 nm.