Theoretical and Experimental Study for FT-IR and UV/VIS Spectra of 1,4-diphenyl-3-(phenylammonio)-1H-1,2,4-triazolium(inner salt) by Using DFT Approach

摘要

In this study, geometrical parameters, vibrational frequencies, electronic absorption maximum wavelengths in gas phase and chloroform solvent, and frontier orbitals (HOMO-LUMO) of 1,4-diphenyl-3-(phenylammonio)- 1H-1,2,4-triazolium(inner salt) were calculated by using DFT/B3LYP method with 6-311G(d,p) basis set. The Fourier Transform-Infrared (FT-IR) solid phase spectrum of the title compound was recorded in the spectral range 4000-400 cm^-1. The difference between the scaled wavenumbers and the observed values of most of the vibrational modes is nearly small. The UV-Vis spectrum was measured in the spectral range 200-800 nm in chloroform solution. The theoretical electronic (UV-Vis) spectrum calculated using the TD-DFT(C-PCM) method with chloroform solvent is more suitable than the gas phase to the experimental spectrum. The calculated HOMO and LUMO energies show that charge transfer occurs within the molecule. Finally, a comparison between the experimental data and the calculated results appeared a good agreement.