The Electronic Properties and Reactivity of 4 (4-Substituted phenyl) -1,2,5- Selenadiazole Derivatives

This study presents a theoretical investigation of 4-(4-substituted phenyl) -1,2,5- selenadiazole derivatives, focusing on the impact of para-substituents on their electronic properties and reactivity. Semi-empirical PM3 and density functional theory (DFT) methods (B3LYP/3-21G) were employed for molecular geometry optimization and electronic structure analysis. Key findings include significant substituent effects on HOMO-LUMO energy gaps, proton affinities, and reactivity indices. Electron-donating groups, particularly NMe2, notably enhanced molecular softness and reduced energy gaps, indicating increased chemical reactivity. Proton affinity calculations revealed systematic trends for electron-donating groups, while electron-withdrawing groups showed less consistent behavior. These insights provide a foundation for the potential application of these derivatives in catalysis, materials science, and drug development, highlighting the utility of computational methods in predicting structure-property relationships.