Description:
<jats:title>Abstract</jats:title><jats:p>The design and development of organic luminophores that exhibit efficient ultraviolet (UV) fluorescence in the solid state remains underexplored. Here, we report that 1,4‐dialkenyl‐2,5‐dialkoxybenzenes and 1,4‐dialkenyl‐2,5‐disiloxybenzenes act as such UV‐emissive fluorophores. The dialkenyldioxybenzenes were readily prepared in three steps from 2,5‐dimethoxy‐1,4‐diacetylbenzene or 2,5‐dimethoxy‐1,4‐diformylbenzene via two to four steps from 1,4‐bis(diethoxyphosphonylmethyl)‐2,5‐dimethoxybenzene. The dialkenyldioxybenzenes emit UV light in solution (<jats:italic>λ</jats:italic><jats:sub>em</jats:sub>=350–387 nm) and in the solid state (<jats:italic>λ</jats:italic><jats:sub>em</jats:sub>=328–388 nm). In addition, the quantum yields in the solid state were generally higher than those in solution. In particular, the adamantylidene‐substituted benzenes fluoresced in the UV region with high quantum yields (<jats:italic>Φ</jats:italic>=0.37–0.55) in the solid state. Thin films of poly(methyl methacrylate) doped with the adamantylidene‐substituted benzenes also exhibited UV emission with good efficiency (<jats:italic>Φ</jats:italic>=0.27–0.45). Density functional theory calculations revealed that the optical excitation of the dialkenyldimethoxybenzenes involves intramolecular charge‐transfer from the ether oxygen atoms to the twisted alkenyl‐benzene‐alkenyl moiety, whereas the dialkenylbis(triphenylsiloxy)benzenes were optically excited through intramolecular charge‐transfer from the oxygen atoms and twisted π‐system to the phenyl‐Si moieties of each triphenylsilyl group.</jats:p>