Regioregular polyalkylthiophenes

A convenient direct route has recently been described for obtaining regioregular polyalkylthiophenes using a tandem iridium-catalyzed borylation to produce the monomer, and a palladium-mediated coupling to produce the polymer [68]. The treatment of substituted thiophenes with B2pin2 in the presence of [lrCl2(COD)]2/ 4,4 -di-tert-butyl-2,2 -bipyridine (DTBPY) provided the expected monomer in 97% yield (Scheme 7.35). 

Obviously, the data pertaining to ordered small molecules stand above that curve, as does the mobility measured by the Bell Labs [111] and Cambridge [112] groups on a regioregular polyalkylthiophene. In a subsequent paper [16], the Philips group extended its model to account for structure ordering. This model will be presented in Section 14.6.1.2. 

Kiriy, N. et al.. One-dimensional aggregation of regioregular polyalkylthiophenes. Nano. Lett. 3, 707-712, 2003. 

Indeed both anodic and FeCls oxidation of symmetrically disubstituted 2,2 -bithiophenes result in highly regioregular polyalkylthiophenes with HH-TT coupling pattern. 

N. Kiriy, E. Jaehne, H.-J. Adler, M. Schneider, A. Kiriy, G. Gorodyska, S. Minko, D. Jehnichen, P. Simon, A. A. Fokin and M. Stamm. One-dimensional aggregation of regioregular polyalkylthiophenes. Nano Lett. 3(6),... 

Figures Supramolecular structure of regioregular polyalkylthiophenes. Reprinted with permission from R.D.

Polythiophenes containing electron withdrawing alkyl carboxylates (35k-351) have also been synthesized.[212] OTFTs fabricated with the regioregular polythiophene (35k) gave mobilities of up to 0.07 cm V s compared to 0.0063 cm V s for the regiorandom polythiophene (351).[212] Another electron-with-drawing moiety, tetrafluorobenzene, has been substituted on the polyalkylthiophene backbone (35m). Spin-cast films of 35m from 0.5 wt % chloroform solution showed a mobility of up to 2 x 10 cm V s. [213]... 

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