Enhancing the Solid-State Emission of Carbonyl-Containing Compounds by Means of Introducing a Bifuran Core

Aromatic aldehydes and ketones are attractive as luminescent
materials
because they exhibit room temperature phosphorescence. However, an
absence of significant luminescence in the solid state limits their
practical application. This study investigates a series of bifuran
dialdehydes and diketones (F1–F3) and their bithiophene analogues
(T1–T3) and compares their photophysical properties in solution
and the solid state. The incorporation of carbonyl groups into bifuran
cores significantly enhances their solid-state fluorescence, with
solid-state quantum yields reaching up to 35%, in contrast to low
fluorescence for the thiophene-based analogues. Structural analysis
via X-ray crystallography reveals that bifuran derivatives exhibit
tighter packing and more rigid molecular backbones, which contributes
to the observed aggregation-induced emission. The carbonyl group also
stabilizes the furan core compared with unmodified bifurans.