Infrared spectra and other properties predictions of 5-amino-3-methyl-4-isoxazolecarbohydrazide with electric field simulation using CPC model

Abstract

Here, the Conductor-like Polarizable Continuum Model (CPCM) was used as a less demanding substitute of Periodic Boundary Conditions (PBC) method to attempt to reliably simulate infrared spectra and some structural parameters of solid compound - 5-amino-3-methyl-4-isoxazolecarbohydrazide (HIX). The measured relative electric permittivity of HIX was used as a simplified equivalent of electric intensity generating by other molecules of 5-amino-3-methyl-4-isoxazolecarbohydrazide in crystal structure. The application of CPCM has resulted in better conformity of calculated molecular parameters with experimentally found. Theoretical geometry was compared with data obtained with X-ray crystallography. Comparison of harmonic approximation with anharmonic one, based on the six selected characteristic vibrations, shows that non-scaled harmonic wavenumbers, calculated with CPCM, well correspond to experimental spectra. Additionally, the results point out that anharmonic approximation appeared to be strong sensitive for input geometry and calculation parameters used, so the results are sometimes unreliable, especially for low wavenumbers. Also, the new feasible ways of the synthesis of the titled compound is presented, one of which is particularly easy and highly efficient.