Note 1: Poly(thiophene-2,5-diyl), often written as poly(thiophene), is the generic polythiophene.

Note 2: Regular polymers of a monosubstituted thiophene are prepared by catalytic coupling polymerization of the corresponding thiophene derivative or its defined dimers (dimers mostly provide regular but regioirregular polymers, see the chart below). Oxidative polymerization of an asymmetric thiophene monomer gives an irregular polythiophene with considerably worse functional properties.

Note 3: Polythiophenes are a subclass of conjugated polymers. The highest practical applications has found poly[3,4-(ethylenedioxy)thiophene] (PEDOT). Regioregular poly(3-alkylthiophenes) are studied as materials for organic solar cells. They become conducting upon oxidative doping.

Examples: Polythiophenes and their structure-based (first row) and source-based (second raw) names are: