Oligosilanyl-Bridged Biscarbazoles: Structure, Synthesis, and Spectroscopic Properties

Abstract

Oligosilanyl-bridged systems are expected to give rise to unique optoelectronic properties because of σ–π conjugation between the Si–Si σ orbital and the aryl π orbital. Herein, we synthesized a small series of novel biscarbazoles bridged with permethylated oligosilanyl units (−[Si(CH 3 ) 2 ] n –, n = 1–4) and examined their spectroscopic properties in detail. In the target molecules BCzSi n , n = 2–4, the efficient σ–π conjugation elevated the highest occupied molecular orbital energy level with no influence on the lowest unoccupied molecular orbital. In the solid state, the emission full width at half-maximum (fwhm) of all the compounds narrowed significantly, while the emission efficiency increased and the emission color of carbazole was retained. This research provided a very simple and general way of subtly manipulating the electronic properties of organic materials to construct an emissive color-retaining system for multifunctional applications.

Multi-state photochromism of bis-tetraarylethene luminogens modulated through oligosilane linkages

“…6 d In the target compounds BTPTSi n ( n = 1–4), oligosilane linkages were introduced through salt elimination reactions reported in our previous works. 13 b ,14 Lithiation of TPT , followed by the reaction with dichlorodimethylsilane or dichlorotetramethyldisilane, yields BTPTSi1 and BTPESi2 , respectively. Triflate end-capped trisilane and tetrasilane reacted with lithiated TPT to generate BTPTSi3 and BTPTSi4 , respectively.…”

Structure and Photophysical Properties of Silane Bridged Tetraphenylethylene-Oligothiophene Derivatives

“…[29] Only a few TPE-based dual-state emitters based on self-assembly system were reported. [30][31][32] Based on our previous research in the field of organosilicon luminescent materials, [12][13]15,[33][34][35][36][37] we speculate that the introduction of substituted silane bridges between TPE and oligothiophene may enhance the luminescence properties of oligothiophene in both solid and liquid states. In this work, we designed a silane-bridged TPE-oligothiophene derivatives.…”

Disilane-bridged architectures: an emerging class of molecular materials

“…Carbazole endcapped molecule 13 was reported. 61 It retained most of the emission color of carbazole; however, it showed high solubility in common organic solvents, high thermostability, and enhanced emission efficacy in the solid states (F F = 0.33). It may have found potential application as deep-blue organic emitters.…”

“…However, in the sixmembered ring the Si-Si-C(naphthyl) bond angle is unusually restricted to 92.47°, which is signicantly smaller than the idealized value of 109.5°for sp 3 -hybridized silicon. The significant strain imposed by the reduced bond angle in the disilanylene moiety of 71 suggests that its Si-Si bond is highly reactive compared to that of other disilanylene-bridged compounds (59)(60)(61)(62)(63).…”