Novel asymmetrical pyrene derivatives as light emitting materials: Synthesis and photophysics

A series of novel substituted pyrene derivatives with asymmetrical groups have been successfully synthesized in excellent yield. Structures of the asymmetrical compound were fully characterized by ¹H-NMR, IR spectroscopy and mass spectrometry. By introducing ethynyl functions to pyrene, we obtained highly efficient blue and green light emitting materials. It has been demonstrated that the emission characteristics of pyrene derivatives have been bathochromatically tuned in the visible region by extending the π-conjugation. The photophysical properties of these compounds were carefully examined in different organic solvents and different concentrations. The electrochemical properties and geometrical electronic structures of the new pyrene derivatives have been investigated by cyclic voltammograms and density functional theory (DFT) calculations.