Long-Range Charge Transfer Driven by External ElectricField in Alkalides M–LCaL–M (M = Li or Na, L = All- cis 1,2,3,4,5,6-Hexafluorocyclohexane): Facially PolarizedJanus-Type Second Order Nonlinear Molecular Optical Switches

Alkalides with large nonlinear optical (NLO) responses exhibit broad applications in electro-optical devices field. In present work, based on alkali (Li and Na) in conjunction with alkaline-earth (Ca) atoms doped into facially polarized all-cis 1,2,3,4,5,6-Hexafluorocyclohexan (C6F6H6), we firstly reported two facially polarized Janus-type alkalides as an external electric field (EEF) induced second order nonlinear optical switches M-LCaL-M (M = Li or Na, L = C6F6H6). The two 4s electrons of Ca atom are, respectively, pushed out by the negative fluorocarbon face of one L and each of them concentrate on one alkali atom and combine with the s electron of the later to form excess electron pair. Owing to the two excess electron pairs (HOMO and HOMO-1), the novel alkalides M--LCa2+L-M- is formed. Interestingly, with continuous increasing of EEF magnitude, the centrosymmetric M--LCa...