Reduction of silver cation in the cavity of diaza-18-crown-6: A theoretical study

The structure and stability of diaza-18-crown-6 (1) complex with silver cation was studied by the density functional method with the PBE functional. The reduction of the cation in the macrocycle cavity was simulated and possible stability of the resulting van der Waals complex of the crown ether 1 with silver atom was analyzed. It is shown that, after electron capture, two equilibrium conformers of Ag+·1 give two structures locally stable with respect to the dissociation into the silver atom and the crown ether in its nearest equilibrium conformation. One of the neutral structures, that of the Cs symmetry, corresponds to a global minimum on the potential energy surface of the Ag0—1 system. It ensures the thermodynamic stability of the reduced complex with respect to dissociation.