Synthesis, characterization and optical properties of a regioregular
and soluble poly[3-(10-hydroxydecyl)-2,5-thienylene]
, Paolo Costa-Bizzarri, Carlo Della-Casa,
Luisa Paganin, Alessandro Fraleoni
Dipartimento di Chimica Industriale e dei Materiali, Universita
di Bologna, Viale del Risorgimento 4, Bologna I-40136, Italy
Received 7 February 2002; received in revised form 18 October 2002; accepted 24 October 2002
The preparation of a regioregular trimethylsilanyloxydecyl 3-substituted polythiophene and its conversion to the corresponding
hydroxydecyl polymer, which is soluble in common organic solvents, is described both in solution and in ﬁlm. The chromic behaviour of the
hydroxy functionalized polymer was investigated by UV–vis spectroscopy in different solvent/non-solvent mixtures and in the solid state by
exposing the polymer adsorbed on hydroxylic matrices to methanol vapours.
q 2002 Elsevier Science Ltd. All rights reserved.
Keywords: Polyhydroxyalkylthiophene; Regioregularity; Post-functionalization
Intrinsically conductive polymers (ICP) have been
studied for many years now for their interesting electric
and electronic properties . In the ﬁeld of polymers, these
materials are indeed of considerable importance and of great
scientiﬁc and industrial interest as testiﬁed to by the Nobel
Prize for Chemistry having been awarded to Heeger,
McDiarmid and Shirakawa in 2000 for their studies on
In addition to the typical properties of ICPs, polyalk-
ylthiophenes (PATs) also possess other speciﬁc character-
istics such as good solubility and processability .The
type of substituent most commonly found in polythiophenes
is the linear alkylic one in the 3-position of the aromatic
ring. The possibility of introducing a functionalization in the
side chain has, however, afforded the opportunity of
modulating the ﬁnal properties of the polymeric material.
Hydroxy-functionalized polythiophenes prepared
through the post-functionalization of soluble precursor
polymers have been recently studied by the authors [3 –5].
This method has permitted not only to overcome the
reduced solubility typical of these materials when they are
directly derived from the monomer through oxidative
polymerization but also to underscore their peculiar proper-
ties, thus making their full characterization possible.
The possibility of forming hydrogen bonds between the
side chains reduces the rotational mobility of the poly-
thiophenic backbone while favouring states which are
conformationally better ordered [6,7].
The present work sets out to synthesize a poly[3-(10-
hydroxydecyl)-2,5-thienylene] (PHDT) (Fig. 1) with high
regioregularity, the purpose being to determine whether the
–OH functionality levels off the conﬁgurational differences
giving comparable chromic effects among different PHDT
samples as already hypothesized . Another objective of
this study was to investigate the behaviour of PHDT in the
solid state by supporting the polymer on different types of
hydroxylated solid matrices and studying the chromic
effects of exposure of the samples to methanol vapours.
PHDT was synthesized starting from the corresponding 2,5-
dibrominated monomer with the hydroxy group protected
by means of the trimethylsilanyloxy group. The transform-
ation from the precursor polymer to PHDT was performed
both in solution and directly on the ﬁlm.
0032-3861/03/$ - see front matter q 2002 Elsevier Science Ltd. All rights reserved.
PII: S 0 0 32 -3 86 1( 0 2 ) 00 80 0- 5
Polymer 44 (2003) 535–545
Corresponding author. Tel.: þ 39-51-2093705; fax: þ39-51-2093257.
E-mail address: firstname.lastname@example.org (M. Lanzi).
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