TY - JOUR ID - TI - DFT conformational study of five-ring bent-core mesogens with a central 1,3‐phenylene unit AU - Shatha Raheem Helal Alhimidi1, Muhsen Abood Muhsen Al-Ibadi2 and PY - 2016 VL - 3 IS - 2 SP - 30 EP - 35 JO - Muthanna Journal of Pure Science (MJPS) مجلة المثنى للعلوم الصرفة SN - 22263284 25725181 AB - The potential energy surfaces of the five-ring bent-core molecules with a central 1,3-phenylene unit,including azobenzene with alkyloxy as terminal chains, has been investigated by using density functional theory(DFT). The PBE1PBE/6-31G(d,p) level of theory has been used for some computations in addition to the BP86function, where used to study the influence of rotation of the connection groups. These computations were performedon the conformational behavior of the connection groups, included ester linkage group, N=N group and terminal ORgroup, of the five-ring bent-core compound in a systematic way. The relaxed rotation barrier with respect tothe six torsion angles (φ1, φ2, φ3, φ4, φ5 and φ6) were calculated. It is interesting to note that the oxygen atoms of thelinkage group, which are directly connected to the rings, give banana-shaped compounds with energy barrier by about0.9 kcal mol-1 and high flexibility, whereas the ester group connected to phenyl ring by a carbon atom shows a highenergy barrier by about 10.2 kcal mol-1 and a relatively limited conformational degree of freedom. The dependency ofthe Dipole moment on conformers with constraints to the torsion angle was studied.

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