Shivaji Babar Suraj, Boddula Rajamouli, Singh Surya Prakash
Polymers and Functional Materials Division, CSIR-Indian Institute of Chemical Technology, Uppal Road, Tarnaka, Hyderabad 500007, India.
Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India.
Phys Chem Chem Phys. 2022 Jun 22;24(24):15110-15120. doi: 10.1039/d2cp01934e.
It is an established fact that [1]benzothieno[3,2-][1]benzothiophene (BTBT) is a champion molecule for high-mobility OFET devices. Recently, it has also been utilized in dye-sensitized solar cells (DSSCs) and organic photovoltaics (OPVs) as an alternative to fullerene (non-fullerene acceptor). Considering the advantageous features of BTBT, we herein report its aggregation-induced emission (AIE) and mechanofluorochromic (MFC) behaviour for the first time. We have designed and synthesized two new BTBT derivatives: [1]benzothieno[3,2-][1]benzothiophene-tetraphenylethylene (BTBT-TPE) and [1]benzothieno[3,2-][1]benzothiophene-phenyl-,-dimethylamine (BTBT-NMe). The donor-π-acceptor-π-donor-integrated BTBT-TPE showed AIE whereas BTBT-NMe showed aggregation-caused quenching (ACQ), as evident by their quantum yield and lifetime results. BTBT-NMe was found to possess great interaction, resulting in the halochromic (protonation) effect. The theoretical calculation of the electronic distribution and energy investigation were consistent with the experimental outcomes. The electron contribution of the HOMO is high for BTBT-NMe at the donor, which can be attributed to the weaker donating nature of TPE compared to that of the NMe group. Overall, the results indicate the potential of the mechanical stimuli and aggregation response of the studied compounds for further investigation.
[1]苯并噻吩并[3,2 - ][1]苯并噻吩（BTBT）是高迁移率有机场效应晶体管（OFET）器件的典型分子，这是一个既定事实。最近，它还被用于染料敏化太阳能电池（DSSC）和有机光伏电池（OPV）中，作为富勒烯（非富勒烯受体）的替代品。考虑到BTBT的有利特性，我们在此首次报道其聚集诱导发光（AIE）和机械荧光变色（MFC）行为。我们设计并合成了两种新的BTBT衍生物：[1]苯并噻吩并[3,2 - ][1]苯并噻吩 - 四苯乙烯（BTBT - TPE）和[1]苯并噻吩并[3,2 - ][1]苯并噻吩 - 苯基 - ， - 二甲胺（BTBT - NMe）。供体 - π - 受体 - π - 供体整合的BTBT - TPE表现出AIE，而BTBT - NMe表现出聚集导致猝灭（ACQ），这从它们的量子产率和寿命结果中可以明显看出。发现BTBT - NMe具有很强的相互作用，从而导致加酸显色（质子化）效应。电子分布的理论计算和能量研究与实验结果一致。在供体处，BTBT - NMe的最高占据分子轨道（HOMO）的电子贡献较高，这可归因于与NMe基团相比，TPE的供电子性质较弱。总体而言，结果表明所研究化合物的机械刺激和聚集响应具有进一步研究的潜力。
