Syntheses of Thiophene and Thiazole-Based Building Blocks and Their Utilization in the Syntheses of A-D-A Type Organic Semiconducting Materials with Dithienosilolo Central Unit

Abstract

Dithienosilole moiety is an electron donating unit, and it has been applied, for example, as a part of small molecular and polymeric electron donors in high performance organic photovoltaic cells. Herein, we report efficient synthetic routes to two symmetrical, dithienosilolo-central-unit-based A-D-A type organic semiconducting materials DTS(Th 2 FBTTh) 2 and DTS(ThFBTTh) 2 . Fine-tuned conditions in Suzuki–Miyaura couplings were tested and utilized. The effect of inserting additional hexylthiophene structures symmetrically into the material backbone was investigated, and it was noted that contrary to commonly accepted fact, the distance between electron donor and acceptor seems to play a bigger role in lowering the E gap value of the molecule than just extending the length of the conjugated backbone. We searched for precedent cases from the literature, and these are compared to our findings. The optical properties of the materials were characterized with UV–vis spectroscopy. Majority of the intermediate compounds along the way to final products were produced with excellent yields. Our results offer highly efficient routes to many heterocyclic structures but also give new insights into the design of organic semiconducting materials.

Theoretical investigations of the substituent effect on the opto‐electronic properties of the linearly fused napthadithiophene‐based molecules

“…A variety of derivatives based on the acene, 7,8 thiopene, 9,10 and perylene 8,11 molecules are widely studied for optoelectronic devices due to their good charge transport properties. Among them, thiophene‐based materials have gained considerable attention due to their ability to tune the physical properties of OSC, such as electronic structure, frontier molecular orbital energy levels, optical properties, and charge carrier mobility 12,13 . In particular, benzodithiophene (BDT) and anthradithiophene (ADT) materials were identified as solution‐processable p‐type and n‐type materials in OFETs and OPVs in recent years 14–18 .…”

The effects of alkyl substitution on the aggregation of π-conjugated dyes: spectroscopic study and modelling

“…This approach allows the design of dyes with intense charge-transfer (CT) transitions in the visible or near-IR, whose position and intensity can be tuned by the number and strength of D and A moieties and their connectivity. [12][13][14] Moving from the molecule to the material, made up of several interacting molecules, the degree of complexity increases enormously. Indeed, the optoelectronic properties of molecular assemblies can be strongly affected by the intermolecular interactions, and aggregation may bring about collective and cooperative effects, allowing larger responses to be obtained than those achievable with single noninteracting species.…”

“…This approach allows the design of dyes with intense charge-transfer (CT) transitions in the visible or near-IR, whose position and intensity can be tuned by the number and strength of D and A moieties and their connectivity. 12–14…”