Perfluorophenyl‐Bifuran: A Stable and Fluorescent Material Exhibiting Mechanofluorochromic Behavior

The photochemistry and photophysics of benzoyl-carbazole

Benzoyl-carbazole and its derivatives are considered a platform for exploring processes such as room temperature phosphorescence (RTP) and thermally activated delayed fluorescence (TADF). They have also been reported to exhibit dual emission, but there is a great spectral variability in the relative intensity of the emission bands reported in different studies. To better understand the fundamental photophysical properties, we set to explore BCz and its perfluorinated derivative F5BCz using spectroscopy and quantum chemical simulations. We find that the reported dual fluorescence in solution and in films results from a photochemical process (photo-Fries rearrangement), producing carbazole among other products, explaining the variation in the reported emission spectra. In addition, BCz exhibits solvent dependent TADF, which is explained by the stabilization of the charge transfer S1 state in polar solvents. F5BCz undergoes an efficient photochemical process (Mallory reaction) from its single state to produce highly fluorescent product c-F5BCz, in 40% isolated yield. This photoreactivity also proceeds in films under ambient conditions, which have significant implications on the applications of BCz-based materials for optoelectronic applications.

Bottom-up modular synthesis of well-defined oligo(arylfuran)s

Oligofurans have attracted great attention in the field of materials over the last decades because of their several advantages, such as strong fluorescence, charge delocalization, and increased solubility. Although unsubstituted or alkyl-substituted oligofurans have been well-established, there is an increasing demand for the development of the aryl decorated oligofuran with structural diversity and unrevealed properties. Here, we report the bottom-up modular construction of chemically and structurally well-defined oligo(arylfuran)s by de novo synthesis of α,β′-bifuran monomers and late-stage bromination, stannylation and subsequent coupling reaction. The preliminary study of the photophysical properties demonstrated that the polarity-sensitive fluorescence emission and high quantum yields in THF solution could be achieved by modulating the aryl groups on the oligo(arylfuran)s. These twisted molecules constitute a new class of oligofuran backbone useful for structure−activities relationship studies. Meanwhile, the experimental studies and calculations showed that tetrafurans have appropriate HOMO energy levels, and could therefore potentially be high-performance p-type semiconductors.

Oligofurans have attracted great attention because of their strong fluorescence, charge delocalization, and increased solubility. Here the authors show a bottom-up modular construction of chemically and structurally well-defined oligo(arylfuran)s by de novo synthesis of α,β′-bifuran monomers and late-stage bromination, stannylation and subsequent coupling reaction.