Can a molecular switch exist in both superalkali electride and superalkalide forms?

Abstract

To combine both electride and alkalide characteristics in one molecular switch, it is shown herein that the phenalenyl radical and the M₃ ring (M₃–PHY, M = Li, Na, and K) stacked with parallel and vertical geometries are good candidates. The former geometry is the superalkali electride e⁻⋯M₃⁺–PHY while the latter geometry is the superalkalide M^δ−–M₂^(1–δ)+–PHY⁻. The superalkalide M^δ−–M₂^(1−δ)+–PHY⁻ may isomerize to the superalkali electride e⁻⋯M₃⁺–PHY (M = Li, Na, and K) using suitable long-wavelength irradiation, while the latter may isomerize to the former with suitable short-wavelength irradiation. Also, applying suitable oriented external electric fields can drive the superalkalide M^δ−M₂^(1−δ)+–PHY⁻ to change into the superalkali electride e⁻⋯M₃⁺–PHY (M = Li, Na, and K). The differences in the static and dynamic first hyperpolarizability (β₀) values between them were also studied.