FT-IR, FT-Raman and UV–vis spectra and quantum chemical investigation of trimetazidine

Abstract

Fourier transform infrared and Raman spectra of trimetazidine (TMZ) were recorded. The structure, geometry optimisation and vibrational frequencies were investigated. The specific mode of normal coordinate analysis was made for the stable conformer of the molecule using restricted Hartree–Fock (RHF) and density functional theory (DFT) calculations (B3LYP) with the 6-31G(d,p) basis set. Comparison of the observed fundamental vibrational frequencies of the molecule and calculated results by RHF and DFT methods indicates that B3LYP is superior to molecular vibrational problems. The thermodynamic functions of the title molecule were also calculated using the RHF and DFT methods. The DFT-optimised geometry was used in the time-dependent DFT and ZINDO calculations to predict the oscillator strength, electronic transition energies between the orbital and wavelength of the transitions. The DFT-based NMR calculation procedure was used to assign the ¹H NMR chemical shift of TMZ. The electron density-based local reactivity descriptors such as Fukui functions were calculated to explain the chemical selectivity or reactivity site in TMZ.

Keywords:

• FT-IR
• FT-Raman
• UV–vis
• ¹H NMR spectrum and trimetazidine

Notes

^1. Presently Registrar, Periyar University, Salem, TN, India

Additional information

Notes on contributors

S. Gunasekaran

1 1. Presently Registrar, Periyar University, Salem, TN, India