Novel Electrochemiluminescent Platinum (II) Schiff-Base Complexes

Abstract

A series of platinum (II) complexes with Schiff base ligands were synthesized and compared in terms of their photoluminescence, electrochemical and electrochemiluminescence (ECL) properties. Photochemical and electrochemical techniques were used to establish the relationship between the photophysical and redox properties. The emission wavelengths (λem) of theses complexes were found to be highly tuneable with shifts of up to 150 nm in the emission resulting from very minor changes in the ligand structure. All reported complexes exhibit intense ECL via both annihilation and co-reactant pathways. The ECL properties are considered in the light of the photochemical and electrochemical properties of each complex as well as the thermodynamics of the ECL reaction in each case. The findings provide useful insights into the favorable characteristics required for efficient ECL and the directions which should be explored in the search for new ECL luminophores.