Cyclopentadithiophene derivatives: a step towards an understanding of thiophene copolymer excited state deactivation pathways

Abstract

In (cis) cyclopentadithiophene, the large Stokes shift is due to a bond length change whereas with α2 (trans) it involves a change in the dihedral angle.

Polymeric near infrared emitters with bay-annulated indigo moieties

“…BAI1 was obtained from double annulation of indigo, 13,19 as described in Scheme 1; 4,4-didodecyl-4H-cyclopenta[1,2-b:5, 4-b 0 ]dithiophene (C 12 CPDT) was synthesized as previously described. 25 4,8-Bis((2-butyloctyl)oxy)benzo[1,2-b:4,5-b 0 ]dithiophene (BDT) was obtained from TCI and used without further purification.…”

“…Due to the chemical structure of the corresponding repeat units (Scheme 1), the monomeric C 12 CPDT or BDT are taken as model donor units of the copolymers. Therefore for PBAIC-1,2 t 0 = 166 ps 25 (related to C 12 CPDT) and for PBAIBD-1 t 0 = 560 ps (related to BDT, Fig. S11, ESI †) were used in eqn (4).…”

“…Room temperature spectroscopic data (absorption and fluorescence emission maxima together with Stokes shift, D SS ) and fluorescence quantum yield (j F ) for the BAI copolymers and model monomers at T = 298 K j F = 0.05 in methylcyclohexane in ref 25…”

Effects of Electron-Donating and Electron-Accepting Substitution on Photovoltaic Performance in Benzothiadiazole-Based A–D–A′–D–A-Type Small-Molecule Acceptor Solar Cells

“…On the basis of the considerations described above, herein, we have designed and synthesized three A–D–A′–D–A-type NFRAs ( BTCPDT , BTCPDTO4 , and BTCPDTF ), in which two cyclopentadithiophene (CPDT) units and one benzo­[ c ]­[1,2,5] thiadiazole (BT) unit is used as D–A′–D with two A units, 2-(5,6-difluoro-3-oxo-2,3-dihydro-1 H -inden-1-ylidene) malononitrile (2FID). The CPDT is a multiple-ring electron-rich moiety with a strong electron-donating ability. − In addition, BT is one of the most commonly used acceptor moieties in low band gap organic semiconductors. , In particular, the CPDT–BT unit has been widely used as a polymer donor because of its near-infrared absorbing property ascribed to a strong push–pull effect between CPDT and BT. − Furthermore, they cross each other at the centered BT and thereby offer an advantage for intermolecular π–π stacking for high charge transport ability . In addition, 2FID was used as a strong electron deficient end group to enhance the ICT effect, which results in red-shifted absorption and a strong extinction coefficient. , In this study, alkoxy and fluorine groups were introduced to the 5,6-position of the BT to investigate the effects of electron-donating and electron-accepting substitutions in the A′ core on the optoelectronic, morphological, and photovoltaic properties of the A–D–A′–D–A-type NFRA-based OSCs.…”

High‐quality freestanding flexible poly(5‐(2,3‐dihydrothieno[3,4‐b][1,4]dioxin‐5‐yl)‐1H‐indole) film: Electrosyntheses, characterization, and optical properties

“…To pander to the fast development of various fields, highly urgent demand is to design and synthesize new molecules used as CP precursors according to the principle of adjustable band gap that affects optical and electrical properties . So far, the CPs based on thiophene units such as bithiophenes, 2‐(thiophen‐2‐yl)furan, dibenzothiophenes, thieno[3,2‐ b ]thiophenes, benzodithiophenes, and cyclopentadithiophenes have been fabricated and constructed various organic electronic and photonic devices.…”