Control of the bandgap of conducting polymers by rigidification of the π-conjugated system

Abstract

Rigidification of E-l,2(2,2'-dithienylethylene) by bridging the thiophene rings with the central double bond leads to a ca. 0.40 eV decrease of the bandgap of the resulting conducting polymer.

Electrochemical synthesis and characterization of the electronic structure of new conjugated polymers from dithienylene vinylene derivatives

“…In contrast, only vinylene units in PDTDVT are at work and the bandgap significantly decreases with respect to PBT [26]. The results reported in this paper are also consistent with the observations published for related compounds [27,28]. The bandgap of PDTDVB is smaller than in PTBT (thio-phene-benzenethiophene; E gopt = 2.2 eV) due to the presence of the vinylene groups.…”

4,5-Dihydrocyclopenta[b]thiophen-6-one

“…This is because the ethylene bridge in the resulting vinylene system flattens the ring and increases the conjugation between the neighbouring thiophene groups. This technique can also be used to control the band-gap in the corresponding polymers (Roncali et al, 1994) The asymmetric unit of the triclinic unit cell of the title compound, I, contains two unique molecules, 1 and 2, Fig 1. These are closely similar and overlay (Macrae et al, 2008) with an r.m.s. deviation of only 0.024 Å.…”

“…For control of the band-gap in the corresponding polymers, see: Roncali et al (1994). For standard bond lengths, see: Allen et al (1987).…”

Field‐Effect Transistors Based on Oligothienylenevinylenes: From Solution π‐Dimers to High‐Mobility Organic Semiconductors

“…[9] In the past few years, we have described the synthesis and characterization of the electronic properties of various series of oligothienylenevinylenes (nTVs). [10] Work carried out on various series of substituted nTVs has demonstrated that these oligomers present the largest effective conjugation and hence the smallest HOMO±LUMO gap among all classes of p-conjugated oligomers of comparable chain extension. [10] Despite these potentially interesting electronic properties, nTVs have practically never been used as active materials for the realization of organic FETs.…”