Résumé:
Density functional theory (DFT) calculations have
been performed to obtain optimized geometries, vibrational
wavenumbers, highest occupied molecular orbital (HOMO)–
lowest unoccupied molecular orbital (LUMO) energies, nonlinear
optical (NLO), and thermodynamic properties aswell as
molecular surfaces for N-(2,3-dichlorophenyl)-2-nitrobenzene–
sulfonamide in different solvents. B3LYP level gives
similar results for geometric parameters and vibration frequencies
in gas phase, water, and ethanol solvents. The most stable
structure, which is defined by the highest energy gap between
HOMO and LUMO, i s obtained in gas phase
(ΔE = 10.7376 eV). Obtained small energy gaps between
HOMO and LUMO demonstrate the high-charge mobility in
the titled compound. The magnitude of first static
hyperpolarizability (β) parameter increases by the decreasing
HOMO–LUMO energy gap. The intensive interactions between
bonding and antibonding orbitals of titled compound
are responsible for movement of π-electron cloud from donor
to acceptor, i.e., intramolecular charge transfer (ICT), inducing
the nonlinear optical properties. So, the β parameter for
title compound is found to be in the range of 5.5255–
3.7187× 10−30 esu, indicating the considerable NLO character.
All of these calculations have been performed in gas phase
as well as water and ethanol solvents in order to demonstrate
solvent effect on molecular structure, vibration frequencies,
NLO properties, etc.
