Three isomeric tetramethyldithienothiophenes, ,2',3'-tetramethyldithie
no(5,4-b:4',5'-d)thiophene 1, 3,2',3'-tetramethyldithieno(4,5-b:5',4'd
)thiophene 2, and 5,2',5'-tetramethyldithieno(3,4-b:3:4'-d)thiophene 3
, have been synthesized. 2 and 3 show quasireversible cyclovoltammetri
c behaviour with halfwave potentials 0.92, and 0.95 V vs SCE respectiv
ely. Two new cation radical salts, (2)(2)PF6 and (2)(2)PF6 have also b
een isolated.