A new look into the quantum chemical and spectroscopic investigations of 5-chloro-1-methyl-4-nitroimidazole

• Vibrational analysis of 5-chloro-1-methyl-4-nitroimidazole is carried out.
• Quantum chemical studies are done by DFT method.
• The 1H and 13C chemical shifts are analysed.
• Electronic transitions are investigated by UV–Visible spectrum.
• The global and local reactivity descriptors are determined.

Optimised geometrical structural parameters, harmonic vibrational frequencies, natural bonding orbital analysis and frontier molecular orbitals are determined by B3LYP and B3PW91 methods. The exact geometry of 5-chloro-1-methyl-4-nitroimidazole is determined through conformational analysis. The experimentally observed infrared and Raman bands have been assigned and analysed. The 13C and 1H NMR chemical shifts of the compound are investigated. The total electron density and molecular electrostatic potentials are determined. The electrostatic potential (electron + nuclei) distribution, molecular shape, size and dipole moments of the molecule have been displayed. The energies of the frontier molecular orbitals and LUMO–HOMO energy gap are measured. The possible electronic transitions of the molecule are studied by TD-DFT method along with the UV–Visible spectrum. The structure–activity relationship of the compound is also investigated by conceptual DFT methods.

The exact geometry of 5-chloro-1-methyl-4-nitroimidazole is determined through conformational analysis. The electrostatic potential (electron + nuclei) distribution, molecular shape, size and dipole moments of the molecule have been displayed. The structure–activity relationship of the compound is also investigated by conceptual DFT methods.Figure optionsDownload as PowerPoint slide