Herein we report the synthesis of symmetrical bis(thieno[3,4-b]thiophene)s and their electrochemical polymerization. The 2,2'-bis(T34bT) has an oxidation peak at 0.73 V for electropolymerization whereas both 4,4'-bisT34bT and 6,6'-bisT34bT have peak oxidation potentials for polymerization at 0.49 and 0.53 V (0.44 V vs NHE), respectively. For comparison, thieno[3,4-b]thiophene (T34bT) polymerizes with an oxidation peak at 0.9 V. Conjugated T34bT polymers prepared from T34bT, 4,4'-bisT34bT, and 6,6'-bisT34bT exhibit similar redox behavior showing oxidation and reduction peaks located at ca. 0.1 V and ca. -0.3 V, respectively, and optical band gaps of ca. 0.9 eV (1377 nm), whereas the conjugated polymer from 2,2'-bisT34bT has redox peaks centered at 0.5 and 0.4 V. Like PT34bT prepared from T34bT, both PT34bTs prepared from 4,4'-bisT34bT and 6,6'-bisT34bT are pale blue to colorless in their oxidized states and sky blue in their neutral forms. PT34bT prepared from 2,2'-bisT34bT is brown in the oxidized state. The conductivities of the PT34bTs from both 4,4'-and 6,6-bisT34bTs were found to be ca. 2 x 10(-5) S/cm in the undoped state, increasing to 0.2 S/cm after iodine doping. The conductivity of PT34bT from 2,2'-bisT34bT was 2 x 10(-5) and 0.007 S/cm in the neutral and oxidized forms, respectively.