Enhancing fluorescence and lowering the optical gap through C P doping of a π-conjugated molecular backbone: A computational-based design approach

Abstract Design principles of organic fluorescent materials are investigated at the molecular level using a first-principles-based computational approach. The design approach incorporates hetero atoms into a conjugated cyclic skeleton by introducing C=P bonds. In particular we report the design of a molecular system of an extended conjugation system that maintains its planarity across the full system, achieving low lying electronic excited states of large oscillator strengths. We also present calculations that confirm the competing process of internal system crossing to be too slow for affecting the actual relaxation following photexcitation.