CONFORMATIONAL EFFECTS ON ELECTRICAL AND SPECTROSCOPIC PROPERTIES OF 1,2-DI(2-THIENYL)ETHYLENES AND CORRESPONDING POLY[(2,2'-DITHIENYL)-5,5'-DIYLVINYLENES]
T. Benincori et al., CONFORMATIONAL EFFECTS ON ELECTRICAL AND SPECTROSCOPIC PROPERTIES OF 1,2-DI(2-THIENYL)ETHYLENES AND CORRESPONDING POLY[(2,2'-DITHIENYL)-5,5'-DIYLVINYLENES], Macromolecular chemistry and physics, 197(2), 1996, pp. 517-528
1,2-Dialkyl-substituted 1,2-di(2-thienyl)ethylenes have been synthesiz
ed and investigated by cyclic voltammetry. The bulk of the alkyl subst
ituents was modulated in order to progressively increase the torsional
angle between the thiophene rings and the plane of the olefinic bond,
from a fully planar structure to highly twisted systems. Distortion m
arkedly affects the UV spectra and the oxidation peak potentials of th
e monomers. The electrochemical polymerization experiments gave the fo
llowing results: i) (E)- and (Z)-dithienylethylene systems produced po
lymers with identical properties; ii) progressive deviation from plana
rity increased the oxidation peak potential of the monomer, as far as
the polymerization was inhibited; iii) long and rigid monomeric units
reduced chain flexibility, leading to materials with low conductivity
and unsatisfactory mechanical properties.