Thienothiophenes compositions comprising a C3-8 secondary or tertiary alkyl group are disclosed. The thienothiophenes may be represented by the formula: where R is C3-8 secondary or tertiary alkyl, e.g., isopropyl, tert-butyl, tert-pentyl, isopentyl, and 2-ethylhexyl, X and X′ are independently selected from the group consisting of H, halogen atoms (e.g., F, Cl, Br, and I), MgCl, MgBr, Mgl, Sn(R′)3, (where R′ is C1-6 alkyl or —OC1-6 alkyl), boronic acid, boronic ester, —CH═CHR″ (where R″ is H or C1-6 alkyl), —OC1-6 alkyl, —COOC1-6 alkyl, —S—COR′″, —COR′″ (where R′″ is H or C1-6 alkyl), —C≡CH, and polymerizable aromatic rings such as phenyl, naphthalene, pyrrole, dithiophene, thienothiophene, thiophene and so forth.