ChemInform Abstract: Fluorescence of Styryl‐substituted Benzenes

Star-Shaped Conjugated Systems

“…Nevertheless, there is an influence of the 1,3,5-trisubstitution to photophysics and photochemistry. For the tristyrylbenzene derivative 25a , a forbidden transition from the ground state S 0 to the excited state S 1 has been discovered, which results in a very long average fluorescence lifetime τ in the nanosecond range of up to 43.6 ns [ 64 ]. The latter is two orders of magnitude larger than that of the linear chromophore stilbene and depends on the solvent, temperature, substitution pattern and the conformers.…”

“…Similar results are revealed for many substituted oligophenylene derivatives 55 [ 154 ]. In case of compound 56a , the S 0 → S 1 transition is not allowed and consequently, the fluorescence life time is rather long, i.e., in the nanosecond regime [ 64 ]. This property may be attributed to the meta position of the substituents since even larger life times have been measured in the series of 1,3-distyryl substituted benzene derivatives.…”

“…1,2,4,5-Tetrakis(oligo(phenylene ethenylene)benzenes (C-5-A-6): The 1,2,4,5-tetrakis(oligo(phenylene ethenylene))benzenes possess only a limited shape persistence owing to the rather large number of seven possible conformers (c.p. Table 1 ) [ 64 ], thus they were not exploited for MOFs or crystal engineering. However, conformational variation is advantageous for the self-organization into soft materials.…”