Pyrene-based asymmetric hexaarylbenzene derivatives: Synthesis, crystal structures, and photophysical properties

Hexaarylbenzenes (HAB) and their derivatives have attracted considerable attention due to fantastic molecular geometry various applications in materials science. Herein, a set of novel, pyrene-based, asymmetric hexaarylbenzene molecules 3a–c 10 were synthesized fully characterized by using 1H/13C NMR, single crystal X-ray diffraction, high-resolution mass spectra (HRMS), UV–Vis fluorescence spectroscopy, as well density functional theory (DFT) calculations. The compounds show tunable-emission color from violet (366 nm) deep blue emission (407 following the order < 3a 3b 3c solution, pyrene-based hexaarylbenzenes red-shift (deep) region (in range 406 466 with narrow full width at half-maximum (FWHM) spectrum films. On other hand, expanding π-conjugated frameworks decreased > hexaphenylbenzene (HPB), exhibited clearer aggregation-induced characterestics. In addition, DFT calculations indicated that there is strong electronic communication between pyrene unit neighboring phenyl rings through-space charge-transfer process, which would play curial role lowering quantum yield aggregation state. Thus, this article provides an efficient synthetic strategy on how design synthesise high-performance FWHM bands for potential organic electronics.