The optical properties and the structure of random copolymers consisti
ng of mono- and disubstituted alkylthiophenes have been studied by opt
ical and NMR spectroscopy. While the optical data are consistent with
the presence of randomly distributed mono and disubstituted units, NMR
spectra reveal that preferential enchainment between monosubstituted
units takes place. Copyright (C) 1996 Elsevier Science Ltd.