The importance and merit of oligomers in the field of conducting polym
ers is demonstrated for some special substituted oligothiophenes. Thes
e oligomers can serve on one hand as model compounds for the correspon
ding polythiophenes. Due to their well-defined chemical structure, i.e
. defined chain and conjugation length; on the other hand, novel Prope
rties of these compounds can be exploited. Synthesis and polymerizatio
n of new annelated heterocycles as model compounds for low band gap-po
lymers is described.