Thienothiophenes polymers

Fig. 1 Building units of conducting polymers, (1) polyacetylene (PA) (2) polypyrrole (PPy), polythiophene (PTh), polyfurane (PFu) (3) polyphenylene (PP) (4) polyaniline (PANI) 5 polyindole (PIND) (6) polycarbazole (PCaz) (7) polyazulene (Paz) (8) polynaphthalene (PNa) (9) polyanthracene (PAnth) (10) polypyrene (PPyr) (11) polyfluorene (PFiu) (12) poly(isothionaphthalene) (PITN) (13) poly(dithienothiophene) (14) poly(thienopyrrole) (15) poly(dithienylbenzene) (1G) poly(3-alkylthiophene) (17) poly(phenylene vinylene) (18) poly(bipyrrole) (PBPy), poly(bithiophene) (PBT) (19) poly(phenylenesulfide) (20) 4-poly(thienothiophene) (21) poly(thienyl vinylene), poly(furane vinylene) (22) poly(ethylenedioxythiophene) (PEDOT).

In 1967 Cava and Pollack obtained derivatives of the fourth, so-called nonclassical , thienothiophene— thieno[3,4-c]thiophene (4), a condensed heterocycle with formdly tetracovalent sulfur (42)j. The reaction of 3,4-bischloromethyl-2,5-dimethylthiophene (141) with sodium sulfide afforded 4,6-dimethyl-lif,3ff-thieno[3,4-c]thiophene (142) periodate oxidation of 142 gave die corresponding sulfoxide (143) in 91% yield. Attempts to convert the sulfoxide (143) into the thieno-[3,4-c]thiophene by the method used for S3mthesizing benzo[c]-thiophene led only to polymer. However, 24% of adduct 144 and 10% of 145 were obtained by refluxing sulfoxide (143) with N-phenylmaleimide in acetic anhydride, indicating that the thieno[3,4-c]-thiophene was formed as an intermediate. 

The reaction of thieno[2,3-A]thiophene (1) or thieno[3,2-6]thiophene (2) with an equimolar amount of bromine in glacial acetic acid gives polymer containing bromine. Thienothiophene 2 is polymerized by HBr or orthophosphoric acid in acetic acid. These polymers turn blue in sulfuric acid. Similar polymers are formed from thienothiophene 1 they turn red in sulfuric acid. Thienothiophene 1 is resinified by concentrated HCl. ... 

Attempts to syntiiesize a monobromo derivative by treating thienothiophene 2 with one equivalent of bromine in glacial acetic acid resulted in a dibromo derivative and polymer. Similar polymers were obtained from thienothiophenes 1 and 2 with hydrogen bromide in acetic acid. ... 

The polymers 612 showed a strong absorption at 481 nm. Two new strong shoulder absorptions at 531 and 580 nm appeared (07JA4112 07MI3574). On the other hand, the thienothiophene derivatives 613 showed an absorption band at 467 nm, while the film displayed absorption at 496 nm (06AM3029 07JA3226). 

Polymers having a central core consisting of [2,3-b]-thienothiophene were prepared having a M > 6000 daltons and M > 9000 daltons and used as semiconductors or charge transport materials in electronic devices. By varying the aromatic or ahphatic content of this material, a X ax between 380 and 462 nm was obtained. 

A new method was developed for the preparation of poly(thienothiophenes) with amide bridges involving the formation of thiophene fragments by transformations analogous to those which are applied in the course of polymer synthesis (2004VMS1674). 

Poly(thienothiophenes), low band-gap conjugated polymers with a polythiophenelike chain where an aromatic thienothiophene moiety is fused to each thiophene ring, were studied using Raman spectroscopy and photoinduced IR adsorbtion (2002JPC(B)3583). 

Reviews on polythiophenes, polysquarines, polybenzenes, etc. have appeared elsewhere, which also discuss the tunability of the bandgap of conjugated polymers [7]. Further sections of this chapter will focus on the synthesis and characterization of the underivatized thienothiophenes (a-c) and conjugated... 

Apart from these, Pomerantz and Ferraris have synthesized 2-substitued T34bT, which was further polymerized by the free 4- and 6-positions to obtain low bandgap conjugated polymers, the details of which will be given in the following sections. Detailed chemistry of thienothiophenes can be found in the reviews by Litvinov et al. [8j. 

Much like PITN and its analogs, various fused thienothiophenes have also found interest as potential precursors for low handgap systems (Chart 12.9). One of the early systems of promise were polymers of dithieno[3,4- 3, 4 -d thiophene (69), initially reported in 1988 hy Tahani and coworkers [91-93] to have an g of 1.1 eV (for a relevant discussion of prior work see Ref. [1]). Since 1995, however, a numher of new reports on poly(dithieno[3,4-( 3, 4 -d]thiophene) (69) have appeared. 

We have recently shown that 3,6-dimethoxythieno[3,2-h]thiophene 21 leads to a polymer presenting low oxidation potential and moderate bandgap (1.7 eV) [74]. The advantage of thienothiophene unit compared to bithiophene one resides in the planar structure and absence of positional isomers. Furthermore, the crystallographic structure of the dimer 22 (Figure 13.1), shows a hilly planar conjugated system stabilized by noncovalent intramolecular sulhir-oxygen interactions. 

A. Klauck-Jacobs, Pentajiuorosulfanyl-suhstituted thienothiophene monomers and conducting polymers, Patent US2007/7241904B2. 

The highest mobilities achieved in solution-deposited polymer transistor devices have been exhibited by thiophene-containing polymers. Thiophene is an electron-rich, planar aromatic heterocycle, which can form a range of conjugated polymers when coupled appropriately [23, 24], The crystalline nature of many thiophene derivatives plays a role in their excellent charge transport properties. In this chapter, we will focus on copolymers of thiophene with the fused unit, thienothiophene, and their structural analogues. 

Thienothiophene Copolymers in Field Effect Transistors 657 Table 17.1 Properties of thienothiophene-containing polymers... 

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