Microsolvation of Triazole in Water: Structural and energetic behaviors

Abstract

In this study, the hydration process of triazole heterocycle, has been explored considering different isomers of triazole-(H₂O) n (n = 1-8) clusters. Among the used (28) density functional (DFT) exchange-correlation functional the M11 functional exhibit the lowest mean absolute deviation (MAD) with respect to the high level DLPNO-CCSD(T)/CBS employed method used as reference. Subsequently, we analyzed the relative stabilities of these clusters over a temperature range of 20-400 K. The results indicate that triazole-water clusters are stabilized by strong hydrogen-bond interactions, and that the most stable configurations adopt compact, folded, cage-like structures. The hydration free energies per water molecule (ΔG) and hydration enthalpies per water molecule (ΔH) at room temperature and over the 20-400 K have been obtained in the framework of the cluster-continuum solvation approach (SMD). Results show that the hydration free energy follow a linear dependence on temperature, while the enthalpy remains nearly constant. For TZ(H₂O)₈ cluster the estimated hydration free energy is computed to be 0.56 kcal/mol, which is in good agreement with the available experimental counterpart ( ≈ 0.48 kcal/mol) supporting the reliability of used computational approach.