Poly dithieno

Thus, many polymers with different conductivity were synthesized. To cite a few, these are polythiophene [158], 3-methylthiophene [159], polymers of 3-thiophene-acetic acid and methyl 3-thiophene-acetate [160], poly(2,5-thienylenevinylene) [161], poly(benzo[h]-thiophene) [162], poly(naphto[2,3-c]thio-phene) [163], poly(dithieno[3,2-h 2, 3 -fii]-thiophene) [164], poly(3- -hexylthiophene)... 

The polymers of 4H-cyclopenta[2,l-b 3,4-//Jdi thiophene derivatives showed absorptions in the range 560-590 nm [03MM2705]. Some monomers are based on the nonaromatic (12 n electrons) 4H-cyclopenta[2,l-fr 3,4-l/]dithiophen-4-yl cation 580a (X = CH+) model which was expected to display a reduced HOMO-LUMO separation, compared to related aromatic fused systems (i.e., 580, X = S, O, NF1) (91JCS(CC)752). Polymers of 580 (X = S) showed absorption at 480 nm. Poly(dithieno[3,4-b 3, 4 -4J thiophene) showed an absorption at 590-610 nm (89SM(28)C507 97MI23). 

Fig. 10.24 Structures of polymers absorbing beyond 600 nm (a) poly(dithieno(3,4-b 2, 3 -d)thiophene), (b) tbiophene/isothianaphthalene copolymers, and (c) a thienyl-pyrrole/benzothiazole copolymer.

Figure 9 shows the discharge curves of a Type I polypyrrole-based, a Type II polypyrrole/poly(3-methylthiophene)-based and a Type III poly(dithieno[3,4-6 3, 4 -d]thiophene-based supercapacitor at 4 mA cm discharge current. Types I and II can be assembled using such conventional heterocyclic polymers as polypyrrole, polyaniline and polythiophene, which are efficiently p-dopable polymers and can easily be chemically or electrochemically synthesized from inexpensive... 

Figure 9. Discharge curves at 4 mA cm of the three types of supercapacitors a) polypyrrole/LiC104 -propylene carbonate (PC)/polypyrrole b) polypyrrole/ LiC104-PC/poly(3-methylthiophene) c) poly(dithieno[3,4-6 3, 4 -rf ]thiophene)/ (C2Hs)4NBF4-PC/poly(dithieno[3,4-b . i, A -d]thiophene), potentiostatically charged at 1.1 V, 1.15 V, and 3.0 V, respectively.

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. 

The remaining isomeric dithienothiophenes, poly(dithieno]3,4-b 3, 2 -d]thiophene) (70) and poly(dithieno]3,4-b 2, 3 -d]thiophene) (71), have also been the subject of a number of studies since their initial preparation in 1997 [106]. As with polymer 69, polymers 70 and 71 were prepared by electropolymerization of the corresponding monomeric dithienothiophenes to give films, which undergo both n- and p-doping processes. 

Taliani, C., et al. 1989. Optical properties of a low energy gap conduction polymer Poly-dithieno [3,4-b 3, 4 -d] thiophene. Synth Met 28 C507. 

Ehrenfreund, E., et al. 2005. Resonant Raman scattering dispersion in poly(dithieno[3,4-fc3, 4 -d]-thiophene) 2ag spectroscopy. Synth Met 150 251. 

Arbizzani, C., M. Catellani, M. Mastragostino, and C. Mingazzini. 1995. N- and p-doped poly-dithieno[3,4-B 3, 4 -D] thiophene A narrow band gap polymer for redox supercapacitors. Electro-chim Acta 40 1871-1876. 

Figure 7.6 Electrical and optical (evaluated by detecting the transmitted light at 490 nm) responses at the 1000th square wave (2 s period) and at the 1010th (8 s) of poly(dithieno 3,2-b 2, 3 -d thiophene), after [21].

C. Quattrocchi, R. Lazzaroni, J. L. Bredas, R. Zamboni and C. Taliani, Theoretical investigation of the structure and electronic properties of poly(dithieno[3,4-fc/3, 4 -conjugated polymer. Macromolecules, 26, 1260-1264 (1993). 

K. Ogawa and S. C. Rasmussen, N-functionalized poly(dithieno[3,2-b 2, 3 - ]pyrrole)s highly fluorescent materials with reduced bandgaps. Macromolecules, 39, 1771-1778 (2006). 

Fig. 29. Structure of (a) poly(4-decylthieno[3,4-b]thiophene) and (b) poly(dithieno[3,4-6 3, 4 ] thiophene).

Prototypes of such supercapadtors of small geometric areas have been developed [126, 127]. 3-MethylPT and poly(dithieno[3,4-b 3, 4 -d]thiophene) have been grown galvanostatically on carbon paper electrodes by electrochemical polymerization of the appropriate monomers. The properties of studied supercapacitors with these materials are comparable to common carbon supercapadtors in the case of the first mentioned polymer and appear to be better in the case of the second polymer [125]. 

The first example of a narrow band-gap polymer is polyisothianaphthene [Structure (8)] with a band gap of near 1.0 eV [74,75]. Other polymers designed and synthesized with the intention of developing narrow band-gap polymers include poly(dithieno[3,4-b 3, 4 -d]thiophene [76], poly-4//-cy clopenta[2,1 -6 3,4-/ ]dithiophen-4-one [77], poly-4-dicyanimethy lene-4//-cyclopenta[2,l-6 3,4-6 ]dithiophene [78], poly(2,3-dihexylthieno[3,4-6]-pyrazine (9) [79], polysquaraines [80], polycroconaines [80], poly-(naphtho[2,3-c]thiophene-fl//-bithiophene) (10) [81], a polymer containing... 

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