Structural, electronic and optical properties of 2,5-dichloro-p-xylene: experimental and theoretical calculations using DFT method

The vibrational spectra including FT-IR and FT-Raman for 2,5-dichloro-p-xylene (DCPX) have been recorded. All the energies, the geometry of the compound and vibrational frequencies of (DCPX) have been calculated using density functional theory (DFT/B3LYP) method coupled with 6-31G* and 6-311+G** functionals. The occurrence of charge transfer was known from the HOMO-LUMO energy gap of DCPX. In order to find out the electronic excitation energies, oscillator strength and nature of the respective excited states, the closed-shell singlet calculation method has been utilized for DCPX. The values of the total dipole moment (mu) and the first order hyperpolarizability (beta) of DCPX have been investigated. The non-linear optical (NLO) behavior of DCPX has been identified from the results of hyperpolarizability values.