Effect of side chain length on the stability and structural properties of 3-(2’,5’-dialkoxyphenyl)thiophenes: a theoretical study

Abstract

We report on the effect of the alkoxy chain length on the thermodynamic properties of neutral and the corresponding radical cations of 3-(2’,5’-dibutyloxyphenyl)thiophene (DBOPT), 3-(2’,5’-diheptyloxyphenyl)thiophene (DHOPT), and 3-(2’,5’-dioctyloxyphenyl)thiophene (DOOPT) and their dimers studied by Hartree-Fock (HF) and Density Functional Theory (DFT) methods. The DFT calculations suggest that dimers of the dialkoxyphenylthiophenes with longer side chains are thermodynamically more stable by about 61.39 kJ/mol than the ones with shorter side chains at the radical cation state. The results correlate well with the experimental observations made during the electrochemical synthesis of these polymers from their monomers.

KEY WORDS: Density functional theory, Hartree-Fock, Dialkoxyphenylthiophenes

Bull. Chem. Soc. Ethiop. 2010, 24(1), 93-102.