Vibrational Modes of Metribuzin: A Theoretical and Experimental Comparison

Abstract

AbstractPesticides are being used in unregulated and excessive amounts to increase crop yield, causing food and water contamination. Continuous consumption of these pesticides can lead to a variety of health problems, including cancer, respiratory problems, neurological disorders, and reproductive problems. Vibrational spectroscopy uses the unique vibrational modes of these chemicals to identify and quantify their composition with high sensitivity, selectivity, speed, and accuracy. Density functional theory (DFT) can accurately model the vibrational response of these pesticides. Metribuzin, with a triazinone type ring structure, is one such commercial weedicide that is widely used but has not been extensively studied in literature, especially the study of its vibrational modes is lacking. Metribuzin's Raman and infrared (IR) vibrational modes were analyzed in the present article. The calculated bond length, Raman, and IR spectra (using aug‐cc‐pVTZ B3LYP level of theory) were experimentally confirmed. All the major vibrational modes of Metribuzin were assigned. Also, the basis set comparison was performed for DFT/B3LYP method for Raman spectrum calculation of Metribuzin. The errors in wavenumber and intensity of the Raman vibrational modes for each basis set were compared. Hence, the complete study of Metribuzin's structure and vibrational modes was presented.