Solvent effect on transformations of triazenes as studied by means of physical chemistry and quantum chemical calculations.

The article focuses on the heterolytic transformations of triazenes in the presence of diazonium cations, emphasizing the influence of solvent nature—protic versus aprotic—on reaction outcomes. Using high performance liquid chromatography, spectrophotometry, and quantum-chemical calculations based on the Hartree–Fock–Rootaan method, the study demonstrates that the yield of 1,3-bis-(4-nitrobenzene)-triazene correlates with the electronic properties of substituents in the azo-component and the donor characteristics of solvents, with non-protic solvents like acetonitrile favoring higher yields. The research proposes a mechanism involving cation-intermediates and highlights that solvent interactions affect both triazenes and diazonium cations, influencing tautomeric equilibria and reaction energetics. These findings contribute to understanding solvent and substituent effects on triazene reactivity in organic chemistry.