Theoretical Investigation of para Amino-Dichloro Chalcone Isomers. Part II: A DFT Structure-Stability Study of the FMO and NLO Properties

The density functional theory (DFT) method using the functional hybrid (B3LYP) and 6-311G(d,p) basis set was utilized for the geometry optimization with dispersion correction, procedure (GO + DC), for the E and Z chalcone isomers-1-(4-aminophenyl)-3-(i,j-dichlorophenyl)prop-2-en-1-one, where (i) and (j) represent the positions of the two chlorine atoms [(2,3), (2,4),(2,5),(2,6),(3,4), and (3,5)] abbreviated (i,j)-chalcone, and 4-(x,y-dichloro-8aH-chromen-2-yl)aniline, where (x = 5,6 and y = 6,7,8,8a) abbreviated (x,y)-chromen isomers. The calculations revealed that E chalcones are the most stable and the 4-(x,y-dichloro-8aH-chromen-2-yl) aniline isomers are the least stable. The (3,5) chalcones were the most stable in both E and Z chalcone series. However, the 4-(5,8a-dichloro-8aH-chromen-2-yl) aniline is the most stable in the series. The isomer stability order is the same as in Part 1, in which the geometry optimization calculation was followed by the dispersion correction single point energy calculation (GO/SPDC) procedure. The procedures (GO + DC) and (GO/SPDC) were used to calculate energies of the highest occupied molecular orbital (HOMO) and lowest-unoccupied molecular orbital (LUMO) and related properties. The order of the HOMO-LUMO energy gap (Delta E-gap) was chromens

Automated summary

The geometry optimization with dispersion correction procedure using density functional theory (DFT) method was carried out to study the stability of E and Z chalcone isomers and chromen isomers. The calculations revealed that the E chalcones were the most stable, while the 4-(x,y-dichloro-8aH-chromen-2-yl) aniline isomers were the least stable. The HOMO-LUMO energy gap order was consistent with the stability order of the isomers.