End‐capped oligothiophenes—new model compounds for polythiophenes

Abstract

A h . Mutw. 4 (1992) Nu. 2 VCH Verlfl~s~e.srils~~hufi m h H , W-694U Weinhehi, 1992 U93S-u648192;U2U2-olo3 $3.50 f .2S/O

Synthesis and Chain‐Length Dependence of the Electronic Properties of π‐Conjugated Dithieno[3,2‐b:2′,3′‐d]pyrrole (DTP) Oligomers

“…Comparison of this value with the experimental results reported for DTP polymers reveals a discrepancy considerably larger than what is generally observed for other series of oligomers and polymers. [29][30][31][32] Thus a l max of 525 nm and bandgap of 2.10 eV have been reported for the polymer prepared by oxidative polymerization of N-octyl DTP using FeCl 3 , [20] while an bandgap of 1.76 eV has been claimed for poly (1). [9] These results together with the difficult electropolymerization of DTP derivatives are consistent with a less efficient polymerization of DTP than, e.g., cyclopentadithiophenes.…”

Thiophene/cyclopentadiene regular copolymers from electrochemical oxidation of dithienylcyclopentadienes

“…The result is a nicely linear plot ( Figure 6) with intercept of 2.2 eV. This value is only slightly lower than that of polythiophene (2.3 eV [3] ). On the other hand the UV-vis spectrum of the monomer in acetonitrile has a maximum at 383 nm, which, compared with terthiophene (350 nm), shows a slight bathochromic effect.…”

“…[2] In fact, calculations assigned it an energy gap (1.7 eV) significantly lower than that of polythiophene (2.3 eV [3] ) but this conclusion could not be confirmed experimentally since the real copolymer was not known.…”

Polymers, Dimers and Radical Cations from Electrochemical Oxidation of Interring-Bridged Thiophene and Thiophene-Phenylene Tetramers

“…For comparison, ideal polythiophene has an optical gap of 2.3 eV (taken similarly, i.e., at the maximum absorption [26] ). An analogous plot of oxidation potentials (Figure 7 b) allows the evaluation of the oxidation potential of the ideal polymer as -0.16 V vs. Ag/Ag + while for polythiophene a value of 0.10 V has been extrapolated.…”

“…An analogous plot of oxidation potentials (Figure 7 b) allows the evaluation of the oxidation potential of the ideal polymer as -0.16 V vs. Ag/Ag + while for polythiophene a value of 0.10 V has been extrapolated. [26] The 0.26 V increase of the valence band edge constitutes ca. 50% of the lowering of the gap (0.5 eV), which indicates that the Fermi levels do not appreciably shift from polythiophene to poly(6).…”