π-Extended Planarized Triphenylboranes with Thiophene Spacers

Abstract

Planarized triphenylboranes extended with thiophene or bithiophene spacers were synthesized, which showed intense fluorescences in solution and reversible redox waves for reduction in cyclic voltammetry. Organic light-emitting diodes (OLEDs) using these compounds as an electron-transporting material were fabricated.

Recent developments in and perspectives on three-coordinate boron materials: a bright future

“…Since 2012, a considerable number of large boron-doped PAHs, such as 29–32 , have been synthesised, 45,130–140 many of which have been examined for use as electron-transporting materials, 138 liquid crystals, 139 battery electrodes, 140 etc. The planarisation of the triarylborane makes π–π stacking easier, thus, e.g.…”

Design and Luminescence Chromism of Fused Boron Complexes Having Constant Emission Efficiencies in Solution and in the Amorphous and Crystalline States

“…Although most conventional organic luminescent dyes show weak emission in the solid state due to aggregation‐caused quenching (ACQ), several strategies for overcoming this problem have been established. For example, brightly luminescent materials have been invented on the basis of the strategy for introducing bulky groups into organoboron compounds and boron complexes, which can show emission in solution . Since the first report on aggregation‐induced emission (AIE) was published, AIE‐active molecules have attracted attention not only for preparing bright solid‐state luminescent materials but also for developing stimuli‐responsive materials .…”

“…For example, brightly luminescent materials have been invented on the basis of the strategy for introducing bulky groups into organoboron compounds and boron complexes, which can show emission in solution. [1][2][3][4][5][6][7][8][9][10] Since the first report on aggregation-induced emission (AIE) was published, [11] AIE-active molecules have attracted attention not only for preparing bright solid-state luminescent materials [12][13][14][15] but also for developing stimuli-responsive materials. [16][17][18] Indeed, so far, a large number of new AIE-active molecules have been applied as bioprobes and environmental sensors.…”

Designs of Functional π-Electron Materials based on the Characteristic Features of Boron

“…36 Kaji and Yamaguchi et al demonstrated that triarylborane units could be incorporated in electron-transporting materials such as 25 for OLED applications. 37 Moreover, Saito and Yamaguchi et al synthesized fully π-conjugated planarized triarylboranes 26 and boron-containing polyaromatic hydrocarbon 27, in which tricoordinate boron is embedded in the polycyclic π-skeletons (Figure 15). 39 These results demonstrate that stabilization by structural constraint is a gateway for a new molecular design of two-dimensional boron-containing π-conjugated materials.…”