Strengthening the acceptor properties of thiadiazoloquinoxalines via planarization

The synthesis and characterization of fused-ring thiadiazoloquinoxaline derivatives are described. The target molecules were studied by UV-Vis absorption, emission spectroscopy and cyclic voltammetry. The optical absorption maximum λmax of the new molecules in solution were shown at 714–774 nm, with the corresponding optical gaps (Eoptg) of 1.44–1.50 eV. Density functional theory calculations were applied for the design and prediction of HOMO and LUMO variations and the corresponding optical absorptions. The thiadiazoloquinoxaline with a phenanthroline moiety showed a liquid crystalline phase as found from 2D-WAXS studies and an electron transporting behavior indicating its potential as an acceptor building block.