Electronic Structure and Thermodynamic Properties of 4-n- heptyl-4́-cyanobiphenyl: A Computational Study

Publication date: 2019Source: Materials Today: Proceedings, Volume 15, Part 3Author(s): Dipendra Sharma, Gargi Tiwari, Sugriva Nath TiwariAbstractStudy of structure–property relationship suggests that the number of carbon atoms in the alkyl chain of 4-n-alkyl-4́-cyanobiphenyl generates the nematic or smectic phase in the liquid crystal series. The 4-n-heptyl-4́-cyanobiphenyl (7CB) is a member of 4-n-alkyl-4́-cyanobiphenyl (nCB) homologous series, which is well known for its electro-optical properties. The 7CB compound is an enantiotropic liquid crystal. It exhibits nematic phase at 30.0°C and isotropic phase at 42.8°C. Optimization of geometry of 7CB molecule has been performed using Hartree-Fock and DFT methods with 6-31G(d,p) basis set. Electronic structure of the 7CB nematogen has been analysed. The MEP, HOMO-LUMO surfaces, molecular and thermodynamic properties such as total energy, dipole moment, entropy, enthalpy and Gibbs free energy have been obtained at room temperature. Infrared spectrum of the 7CB molecule has been examined vis-a-vis experimental data available in literature.
Source: Materials Today: Proceedings - Category: Materials Science Source Type: research