2,6-Bis(tributyltin)benzo[1,2-b:5,4-b’]dithiophene: a new synthon for organic semiconductors

Abstract

A new tin-functionalized benzo [1,2-b:5,4-b']dithiophene building block was synthesized that can provide access to a series of further extended π−conjugated materials for Organic Field-Effect Transistors (OFETs) via Stille coupling protocol, as exemplified in two cases. The synconfigured benzodithiophene scaffold complements the well-established (anti) benzo [1,2-b:4,5-b']dithiophene unit that has already been successfully employed in OFET devices. DFT-quantum theoretical calculations on a series of organic semiconductors support the selective modification of the band gap by either changing the HOMO, the LUMO, or both. The suitability of the tinfunctionalized synthon to efficiently access a variety of organic semiconductor materials with different properties was also confirmed by the study of their photophysical features.

Designing Organic Semiconductors with Ultrasmall Reorganization Energies: Insights from Molecular Symmetry, Aromaticity and Energy Gap

“…45−51 Compared to the dual substitution scheme, single-thiophene termination (29,33,37) is less effective in reducing λ at a similar molecule length. The benefit of designing dual thiophene-terminated benzothiophenes consistently holds for lateral expanded models (42,43,44,46,48 with λ in the range 46−126 meV), which are derivatized from 2D PAHs (9,10,11,12). Akin to what was found in 2D PAHs, 2D benzothiophenes that include more and longer linear D 2h building blocks tend to have smaller reorganization energies.…”

“…As seen in Figure c, for < 30 – 32 >, < 34 – 36 >, and < 38 – 40 >, dual thiophene-terminated molecules ( 30 , 34 , 38 ) in D 2 h symmetry give the smallest λ among isomers. 38 has a record-small λ (26 meV), which is nearly a quarter of the energy calculated for pentacene (96 meV) and dianthra­[2,3-b:2′,3′-f]­thieno­[3,2- b ]­thiophene (86 meV) and is also far smaller than those of the already synthesized compounds ( 27 , 28 , 29 , 31 , 32 , 35 , 36 , 39 , 40 ). − Compared to the dual substitution scheme, single-thiophene termination ( 29 , 33 , 37 ) is less effective in reducing λ at a similar molecule length. The benefit of designing dual thiophene-terminated benzothiophenes consistently holds for lateral expanded models ( 42 , 43 , 44 , 46 , 48 with λ in the range 46–126 meV), which are derivatized from 2D PAHs ( 9 , 10 , 11 , 12 ).…”

“…Learning from a total of 98 molecules condensed by benzene and/or thiophene rings, we found that linear compounds (6,13,38) in D 2h symmetry have the smallest reorganization energies (96, 64, 26 meV) in each of the three molecular categories (PAHs, thienothiophenes, benzothiophenes). 2D expanded analogues (42,44,46,48) that contain these D 2h building blocks also give unusually small λ (<100 meV). λ of 1D elongated polycyclics show an approximate linear correlation with the ring-averaged HOMA indices and the HOMO−LUMO gaps.…”

X-Shaped donor molecules based on benzo[2,1-b:3,4-b′]dithiophene as organic solar cell materials with PDIs as acceptors

“…55 The value of transfer integrals is also dependent on the relative position of interacting molecules and their FMO distribution patterns. 42,56 To obtain quantitative charge transfer properties, in terms of transfer integral and dri mobility, we also carried out calculations in the crystalline state. On the basis of suitable optical and electronic characteristics, we chose D1 as representative to study its charge transport property in the solid state.…”

The ratio and topology effects of benzodithiophene donor–benzooxadiazole acceptor fragments on the optoelectronic properties of donor molecules toward solar cell materials

“…In this study, we chose benzo[1,2-b:4,5-b 0 ]dithiophene (BDT) as an electron-donating unit (D), it is attractive for use due to its structural symmetry and rigid fused aromatic system properties which can enhance electron delocalization and improve charge mobility. [24][25][26] Ethyne was used as a p-spacer (S), which assists the fine-tuning of molecular planar configurations by lowering the steric hindrance. 27 Although thiophene is a more commonly used p-spacer than ethyne, we chose ethyne instead of thiophene due to its simplicity to carry out such wide investigation analysis, it could help to collect vast calculation data by saving time.…”