Enhanced Photoabsorption and Radiative Decay Rate Constant on Fused Planar Fluorene-Stilbene Frameworks: Experimental and Computational Studies.

This study reports the synthesis and characterization of two novel carbon-bridged oligo(phenylenevinylene) (COPV)-fluorene alternating fused molecules, FLCOPVFL and COPVFLCOPV, designed to enhance light absorption and emission in the blue spectral region. Both compounds exhibit high molar extinction coefficients, blue photoluminescence with quantum yields of 0.91 and 0.92, respectively, and large radiative decay rate constants. Computational studies reveal strong electronic interactions between COPV and fluorene units, resulting in enhanced transition oscillator strengths. Further comparative analysis of two coplanar π-conjugated systems, COPVs and ladder-type poly(p-phenylene)s, highlights the difference in conjugation propagation properties. These findings provide valuable insights for designing advanced π-conjugated systems with tailored optical and electronic functionalities, paving the way for their optoelectronic applications.