Knowledge Bank

In metallic chelates containing two different ligands (A-M-B), a new electronic transition arises which is uncharacteristic of complexes containing either of the ligands separately (i.e., $MA2$ or $MB2$). Such intramolecular transmetallic charge transfer transitions in the A-M-B chelate give rise to absorptions at longer wavelengths than in either the $MA2$ or $MB2$ chelates. The lowest energy transition is determined by the relative ionization potentials of the two ligands A and B. Results of absorption and luminescence spectra will be discussed.