DFT Prediction of Factors Affecting the Structural Characteristics, the Transition Temperature and the Electronic Density of Some New Conjugated Polymers

Conjugated polymers are promising materials for various cutting-edge technologies, especially for organic conducting materials and in the energy field. In this work, we have synthesized a new conjugated polymer and investigated the effect of distance between bond layers, side-chain functional groups (H, Br, OH, OCH and OC H ) on structural characteristics, phase transition temperature (T), and electrical structure of C H OS using Density Functional Theory (DFT). The structural characteristics were determined by the shape, network constant (a, b and c), bond length (C-C, C-H, C-O, C-S, C-Br and O-H), phase transition temperatures, and the total energy (E ) on a base cell. Our finding shows that the increase of layer thickness (h) of C H OS-H has a negligible effect on the transition temperature, while the energy bandgap (E ) increases from 1.646 eV to 1.675 eV. The calculation of bond length with different side chain groups was carried out for which C H OS-H has C-H = 1.09 Å; C H OS-Br has C-Br = 1.93 Å; C H OS-OH has C-O = 1.36 Å, O-H = 0.78 Å; C H OS-OCH has C-O = 1.44 Å, O-H =1.10 Å; C H OS-OC H has C-O = 1.45 Å, C-C = 1.51Å, C-H = 1.10 Å. The transition temperature (T) for C H OS-H was 500 K < T < 562 K; C H OS-Br was 442 K < T < 512 K; C H OS-OH was 487 K < T < 543 K; C H OS-OCH was 492 K < T < 558 K; and C H OS-OC H was 492 K < T < 572 K. The energy bandgap (E ) of Br is of E = 1.621 eV, the doping of side chain groups H, OH, OCH and OC H , leads to an increase of E from 1.621 eV to 1.646, 1.697, 1.920, and 2.04 eV, respectively.