Electron-withdrawing group effects on the structural, electronic, reactivity, and binding characteristics of triazolopyrimidine herbicides: a comparative study of diclosulam, cloransulam-methyl, and cloransulam

Abstract

Diclosulam (DS, I), cloransulam-methyl (CSM, II), and cloransulam (CS, III) are widely used herbicidal inhibitors of the AHAS/ALS enzyme for selective weed control. In the present work, a comparative experimental and theoretical study has been conducted on the impact of substituents on their structural, electronic, and reactive properties. Structural differences have been established using single-crystal X-ray diffraction. The crystal packing and interaction energy have been investigated using the Hirshfeld surface approach, while density functional theory confirmed the experimental geometry. The analysis of the electronic structure, reactivity descriptors, localization of electrons, and non-covalent interactions was carried out by the methods of frontier molecular orbitals, MEP, ELF/LOL, and RDG calculations. The binding interactions of compounds with AHAS/ALS protein targets were determined using molecular docking. The combined results reveal clear interdependencies between the structure, electronic properties, non-covalent interactions, and the behavior of molecules upon the interaction with enzymes.