The Electronic Structure, Stability, Thermodynamics And Vibrational Study of Cis Alkenyl Substituted Chalcones by Density Functional Theory Calculations

In this research, structural analysis and stability of six cis chalcone conformers were investigated, compared with trans conformers using the DFT-B3LYP method and basis set 6-311++G(d,p). Results obtained found that 1-Butenyl cis Chalcone (1-BC) possesses the greatest stability. The polarity of the solvent and the geometry of the conformer appeared to have a significant impact on the stability of the conformers. Additionally, cis 1-BC was appeared to cause the greatest shifts (7 cm-1-gas,6 cm-1-n-hexane and 6 cm-1-ethanol) in the magnitudes of vibrational frequencies of cis unsubstituted CA followed by cis divinyl chalcone (DVC) and cis E-propenyl chalcone (E-PC). It is revealed that the 2-butenyl chalcone (2-BC) constitutes the highest values of Thermal-Energy (T-E), Entropy- (S) and Heat -Capacity (Cv).