Probing the Recognition of Halide and OxyAnions in the Polarprotic and Polaraprotic Solvent Mediums with Neutral UreaBased Receptors: A Computational Study

The dynamical nature of the anion recognition with urea-based receptors in polar protic and polar aprotic solvents is scarce in the literature. We report here, the host–guest binding properties of urea and its derivative 1,3-bis-(4-nitrophenyl)-urea with common anions (F⁻, Cl⁻, OAc⁻, H₂PO₄ ⁻) in the aqueous phase and acetonitrile medium using molecular dynamics (MD) simulations. The MD simulations reveal that the halide analytes are on an average distance (∼14.0 Å) from the receptor moiety in water. The oxy-anions showed better interaction with the receptor molecules in such solvent conditions. In pure acetonitrile medium, the interaction of analytes was very strong with the receptor molecules and the average distance calculated was in the range of ∼1.0 Å to ∼4.0 Å. To unravel the intricacies of sensing the anions with organic receptor molecules in polar solvent mediums, molecular dynamics simulations can be better approach with bulk solvation effect.