3-methylthiophene/3-dodecylthiophene

A range of copolymers involving functional thiophenes have also been formed electrochemically. For example, Sato and coworkers12 formed a copolymer containing 3-dodecylthiophene and 3-methylthiophene. The material had a solubility of 75 (w/w)% in chloroform and a conductivity of 220 S cm-1. 

As with polypyrroles, the counterion used during electropolymerization influences the conductivity of polythiophenes.120121 Electrochemically produced copolymers122 of 3-dodecylthiophene (DTh) and 3-methylthiophene (MTh) have been shown to exhibit conductivities intermediate to the two homopolymers. The actual value depends on the ratio of MTh to DTh in the polymer. 

FIGURE 13.7 Tapping mode AFM phase images of polymer thin films (a) poly(3-hexylthiophene) (b) poly(3-hexylthiophene)-b-polystyrene (c) poly(hexylthiophene)-fc-poly(butylacrylate) (d) poly(3-hexylthiophene)- -poly(methylacrylate) (e) poly(3-dodecylthiophene-ran-3-methylthiophene). Reprinted with permission from [83], Copyright 2006 American Chemical Society. 

With the aid of NMR spectroscopy ( H- H NOESY) for PDDT and its copolymer with 3-methylthiophene in deuterated chloroform, the configurational structures were determined [90,91]. The 3-dodecylthiophene monomer is proved to be attacked predominantly at the p position of the thiophene ring (head) with a probability of 82% during the electrochemical polymerization [90]. PHT prepared by using a zero-valent nickel complex contains a larger proportion of HH units than HT units [92]. Chemically polymerized poly-(3-cyclohexylthiophene) contains HT and HH-TT coupled components in the ratio of 7 3 [93]. 

PT, polythiophene PMT, poly(3-methylthiophene) PHT, poly(3-hexylthiophene) POT, poly(3-octylthiophene) PDT, poly(3-decylthiophene) PDDT, poly(3-dodecylthiophene) PMBET, poly(3-(2-(3-methylbutoxy)ethyl)thiophene) A, tetracyano-p-quinodimethane and its derivatives. 

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