Poly thienylene vinylene

A systematic study of the effect of molecular weight on the photovoltaic performance has also been performed on poly(3-hexadecylthienylene vinylene) synthesized by ADMET polymerization [164]. The molecular weights of the polymers ranged from 6.0x10 to 3.0 X lO gmoD, and were incorporated into bulk heterojunction solar cells with [6,6]-phenyl-Cg -butyric acid methyl 

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Heteroaromatic ring stmctures can also be incorporated into poly(arylene vinylene) stmctures using the same precursor polymer method shown for PPV. Poly(thienylene vinylene) (13) (113—118) and poly(furylene vinylene) (14) (119,120) have been prepared in this manner. In addition, alkoxy-substituted poly(thienylene vinylenes) (15) (119,121) have been synthesized. Various copolymers containing phenjiene, thienylene, and furylene moieties have also been studied (120,122,123). 

Polyacetylene is considered to be the prototypical low band-gap polymer, but its potential uses in device applications have been hampered by its sensitivity to both oxygen and moisture in its pristine and doped states. Poly(thienylene vinylene) 2 has been extensively studied because it shares many of the useful attributes of polyacetylene but shows considerably improved environmental stability. The low band gap of PTV and its derivatives lends itself to potential applications in both its pristine and highly conductive doped state. Furthermore, the vinylene spacers between thiophene units allow substitution on the thiophene ring without disrupting the conjugation along the polymer backbone. 

Electron-Deficient Polymers - Luminescent Transport Layers 16 Other Electron-Deficient PPV Derivatives 19 Electron-Deficient Aromatic Systems 19 Full Color Displays - The Search for Blue Emitters 21 Isolated Chromophores - Towards Blue Emission 21 Comb Polymers with Chromophores on the Side-Chain 22 Chiral PPV - Polarized Emission 23 Poly(thienylene vinylene)s —... 

Another approach to CPL is the synthesis of conjugated polymers with intrinsic chiro-optical properties. A variety of polymers with CPPL have been synthesized so far. Most of them are based upon well-known conjugated polymers such as poly(thiophene)s [4,111], polyphenylene vinylene)s [123], poly(thienylene vinylene)s [124], ladder polymers [125], PPPs [126], polyphenylene ethynylene)s, [127] and poly(fluorenes) [128]. All of them have been modified with chiral side-chains, which induce the chiro-optical properties. 

JJLM Comelissen, E Peeters, RAJ Janssen, and EW Meijer, Chiroptical properties of a chiral-substituted poly(thienylene vinylene), Acta Polym., 49 471-476, 1998. 

Current state-of-the-art hole-transport and electron-transport materials [50] are shown in Figure 6.15. Hole-transport materials include oligo- (58) and polythiophenes (59) [51], poly(thienylene vinylenes) (60) [52], and pentacenes [53] (61). Electron-transport materials include copper phthalocyanine (3), hexadeca-fluoro copper phthalocyanine (62), naphthalenetetracarboxy dianhydride (63), and perylene tetracarboxy dianhydride (64). 

Regioregular head-to-tail poly(3-alkylthiophene) Poly(thienylene-vinylene) from soluble precursor... 

Prins P, Candeias LP, van Breemen AJJM, Sweelssen J, Herwig JPT, Schoo HFM, Siebbeles LDA. (2005) Elecnon and hole dynamics on isolated chains of a solution-processable poly(thienylene vinylene) derivative in dilute solution. Adv Mater 17 718-723. 

In fact, for conjugated polymers, E results from a combination of a and tr bonds (the latter being equal to t ) and E,j is dominated by the interchain transfer integral, Thus, the inequalities imply that, quite generally, the conductivity and the mechanical properties will improve in a correlated manner as the degree of chain alignment is Increased. This prediction is in excellent agreement with data obtained from studies of the poly(3-alkylthiophenes), the poly(phenylene vinylenes), poly(thienylene vinylene) and polyacetylene [27]. 

Nguyen L. H., Gunes S., Neugebaner H., Sariciftci N. S., Banishoeib F., Henckens A., Cleij T., Lutsen L. and Vanderzande D. (2006), Precursor route poly(thienylene vinylene) for organic solar cells photophysics and photovoltaic performance . Solar Energy Mat. Solar Cells 90, 2815-2828. 

Poly(thienylene vinylene)s - A Stable Class of Low Band-Gap Materials... 

Parent poly(thienylene vinylene) has also been synthesized by an aldol precursor route [122]. In this method, 5-methyl-2-thiophenecarbaldehyde 76 is treated with a base and the monomer polymerizes yielding a precursor 77 which is soluble in water. Thermal treatment in an acidic solution at 80 °C yields the fully conjugated material. Alternatively, the solid polymer may be heated to 280 °C to effect elimination of water. Fully conjugated material exhibits low conductivity (10 S cm ) in its pristine state. 

Poly(thienylene vinylene) based block copolymers as small band gap materials... 

A small band gap poly(thienylene vinylene) macro-initiator 9 has been synthesized by Homer-Wadsworth-Emmons condensation. Rod-coil copolymers 10 have been obtained from it (Figure 7) they present red-shifted absorption spectra, which is very suitable for photovoltaic applications. 

Girotto C, Cheyns D, Aernouts T, Banishoeib F, Lutsen L, Cleij TJ, et al. Bulk heterojunction organic solar cells based on soluble poly(thienylene vinylene) derivatives. Org Electron 2008 9(5) 740-6. 

FIGURE 10.10 Chemical structure of low bandgap polymers. PTPTB, (poly-AT-dodecyl-2,5,-bis(2 -thienyl)pyr-role,2,l,3-benzothiadiazole PTV, poly(thienylene vinylene). 

Poly(thienylene vinylene) was prepared by the Wittig reaction [127]. The reaction of diformylbenzene (61) with bisphosphonium salt (69) produced powdery polymer (70), which showed a Amax of 550 nm in KBr. 

FIGURE 10.2 (a) Polyaniline in oxidized state (y= 1 leucoemeraldine y=0.5 emer-aldine y = 0 pemigraniline) (b) polypyrrole (c) polyphenylene vinylene (d) polythi-enopyrrole (e) poly(paraphenylene) (f) polythiophene (g) polyphenylene sulfide (h) polyfuran (i) poly(diphenylamine) (j) polypyridine (k) polyfluorene (1) poly(phenylene vinylene) (m) polyacetylene (n) poly(thienylene vinylene) (o) poly(furylene vinylene) and (p) poly(3,4-ethylenedioxythiophene). 

Poly-(2,5-thiophenediyl vinylene) Poly thienylene vinylene)... 

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