Structure, Stability, and Nature of Bonding Between High Energy Water Clusters Confined Inside Cucurbituril: A Computational Study

Publication date: Available online 21 December 2018Source: Computational and Theoretical ChemistryAuthor(s): Natarajan Sathiyamoorthy Venkataramanan, Ambigapathy Suvitha, Ryoji SaharaAbstractThe structure and stability of the high energy water molecules inside the CB7 cavity was studied using the dispersion corrected density functional theory and molecular dynamics. The intermolecular distance between the O and H in the water molecule was found to decrease upon the encapsulation of water molecules inside the cavity, indicating the increase in the stability of water clusters. The computed binding energies were found to be sensitive to the choice of functional. Energy decomposition analysis (EDA) shows that the repulsive Pauli interaction decides the stability of the water complex. In all the encapsulated systems, except the eight water clusters, the electrostatic interactions have supremacy over the dispersive term, due to the large polarization induced by the water clusters. Molecular electrostatic potentials of entrapped systems show the charge distribution between CB7 and water clusters. QTAIM analysis indicates the existence of noncovalent intramolecular interactions between CB7 and water clusters and ellipticity values to be least for 8H2O@CB7. The topological of ρ(r) fields at the urido nitrogen plane in CB7, proves the stronger bonding with water molecules. Thus, entrapped water molecules are not electronically innocent inside the cage and have noncovalent interaction ...

Source: Computational and Theoretical Chemistry - December 21, 2018 Category: Chemistry Source Type: research