Thieno[3,2-b]thiophene Thieno[3,2-b]thiophene Synonyms: 1,4-DITHIAPENTALENE; 1,4-THIOPHTHENE; BUTTPARK 145\50-51; 1,4-Dithiapentalene 1,4-Thiophthene; THIENO[3,2-B]THIOPHENE; 4-Dithiapentalene 1,4-Thiophthene; Thieno[3,2-b]thiophen CAS NO.: 251-41-2 Formula: C6H4S2 Weight: 140.22596