Tuning of the HOMO–LUMO gap of donor-substituted symmetrical and unsymmetrical benzothiadiazoles
作者:Rajneesh Misra、Prabhat Gautam
DOI:10.1039/c4ob00629a
日期:——
electrochemical reduction show multiple reduction waves. The optical HOMO–LUMO gap of BTDs 5–12 was found to be a function of the number and nature of the acceptors. Computational studies reveal that strong cyano-based acceptors, dicyanoquinodimethane (DCNQ) and tetracyanobutadiene (TCBD) lower the LUMO level in BTDs 7–12, which results in a low HOMO–LUMO gap compared to acetylene linked BTDs 5 and 6. The BTDs with
本文报道了D–π–A–D,D 1 –π–A–D 2,D 1 –A 1 –A 2 –类型的供体取代的对称和不对称苯并噻二唑(BTD)5–12的设计和合成。D 2,D–A 1 –A 2 –D和D–A 1 –A 2 –A 1-D由乌尔曼(Ullmann),铃木(Suzuki)和环加成-逆电环化反应。研究了其光物理,电化学和计算性质,并显示出大量的供体-受体相互作用。它们的单光子吸收在近红外(NIR)区域显示出很强的电荷转移带,电化学还原显示出多个还原波。发现BTD 5-12的HOMO-LUMO光学间隙是受体数量和性质的函数。计算研究表明,强的基于氰基的受体,双氰基喹二甲烷(DCNQ)和四氰基丁二烯(TCBD)降低了BTD 7-12中的LUMO含量,与乙炔连接的BTD 5和6相比,导致HOMO-LUMO间隙低。。具有咔唑和单个TCBD和DCNQ受体的BTD表现出更好的热稳定性。