| Abstrakt: |
Glyphosate is the most widely used broad-spectrum agrochemical, particularly due to its non-selective action mechanism. However, there are concerns regarding its use and possible threat to aquatic and terrestrial lifeforms and the environment. This article aims to better understand the effect of pH on the structural, spectroscopic, and physicochemical properties of glyphosate-based structures, as well as its degradation and respective intermediates. [Display omitted] • A discrepancy of lipophilicity between the theoretical models in basic medium. • Zwitterions show a high lipophilic character in basic medium. • Insights into the degradation from a theoretical mass spectrometry approach. • Solvent has a considerable effect on the chemical shifts of zwitterions. • The spectroscopic properties can be used to describe the structures of zwitterions. Glyphosate is the most used broad-spectrum agrochemical due to its non-selective action mechanism. However, there are concerns regarding being a threat to aquatic and terrestrial lifeforms and the environment. In this study, we conducted a systematic theoretical investigation of the effect of pH on the electronic structure, physicochemical, and spectroscopic properties (IR, Raman, UV–vis, ECD, EI-MS, and NMR) of glyphosate and its zwitterionic structures. The lipophilicity of the zwitterions was studied with ADMET and DFT, and a significant discrepancy between the models was observed. Theoretical EI-MS provided insights into the degradation pathways and possible intermediates. The effect of protonation and hydration on the magnetic properties was described based on an implicit-explicit strategy to compute NMR chemical shifts for the zwitterions, in which the solvent has a considerable effect on the chemical shifts. Overall, our findings suggest that spectroscopic properties can be used to describe glyphosate-based zwitterionic structures. [ABSTRACT FROM AUTHOR] |
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