Copolymers from thiophene/octylthiophen

The shift to lower energy of the absorption maximum of HT-HT coupled PATs is up to 14 nm in solution, 46 nm in the solid state, and other intensive lower energy peaks with shifts of up to 129 nm (609 nm) from the normal PATs [95]. A blue shift of the absorption maximum with increasing coplanar block length is observed in copolymers of thiophene and HH coupled 3-octylthiophene, which interrupts the coplanarity of the polymer backbone [504]. In PHT and in copolymers of thiophene/HH coupled 3-octylthiophene it was found that, with increasing HT-HT coupling content,... 

Pomerantz et al. [49] showed that the molecular weight of this polymer, which was prepared from the chemical oxidation of an equimolar mixture of both monomers, is very high A/w = 4.42 x 10 and A/ = 1.59 x 10. Based on X-ray diffraction measurements. Fell and his co-workers [83] found a correlation between structure and composition of these copolymers. According to them, the samples are partially crystalline with structures intermediate between those of both homopolymers. In the crystalline area, stacks of thiophene chains, equally spaced by the side-chains, form a lamellar structure, and the distance between adjacent stacks varies linearly with the concentration of octylthiophene units in the copolymer. 

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