Molecular Spin Switch and Conversions of Localized Excess Electrons under External Electric Field: Solvated Dielectron C20F20@K@C20F20@K@C20F20

By doping two potassium atoms among three C20F20 cages, peanut-shaped single molecular solvated dielectron C20F20@K@C20F20@K@C20F20 as new type of spin molecular switches was theoretically presented. The triplet structure with two single-excess-electrons individually inside left and middle cages is thermodynamically more stable than the singlet one with lone pair of excess electrons inside middle cage. It is found that applying an oriented external electric field (OEEF) of 111 × 10-4 au (0.5705 V/Å) or -120 × 10-4 au (-0.6168 V/Å) in the x-axis direction firstly and then releasing it, the field-free triplet C20F20@K@C20F20@K@C20F20 with two single-excess-electrons can change into singlet one with lone pair of excess electrons through a singlet one with lone pair of excess electrons inside the end cage. Different spin states can bring significantly different dipole moment component values and considerable different intensities of maxumum wavelengths in intense absorption band. Therefore, C20F20@K@C20F20@K@C20F20 is a good candidate for spin molecular switching materials.