Conformational analysis and electronic properties of fluoromethylfuran oligomers: semiempirical and DFT study

Abstract

Structural and electronic properties of oligomers of fluoromethylfurans (FMFs), OC4H4-CHnF3-n with n = 1, 2, 3 and 4 have been studied using ZINDO/AM1 and B3LYP/6-31G(d) basis set. Preliminary study using AM1 and ab initio (HF) 6-31G(d) with medium basis set was carried out on di-, tri- and tetramer FMFs in order to investigate the stability of configuration of the polymer chains and conformation analysis of the dimers. There is noticeable effect of substituents on the geometries of FMFs as compared to polyfuran, polymethylfuran and chloromethylfuran (CMF) analogues [11]as well as improved characteristics as conducting polymers compared polymethylfurans and CMFs. The most stable conformation is the anti-planar conformation except in fluoromethylfuran in which antigauche conformation is most stable. The energy band gaps, electronic spectroscopy and electronic dipole moment vectors of the compounds are presented. Generally FMFs present lower energy band gaps, longer wavelength and higher electric dipole moments and are therefore more suitable as monomer for conducting polymer especially trifluoromethylfuran.