Electron-transfer in solid is crucial to switchable magnetic, electrical, optical, and mechanical properties. However, it is a formidable challenge to control electron-transfer behaviors via manipulation of crystalline phases, especially through dynamic crystalline transformation. Herein, three crystalline phases of an {Fe2Co2} compound were obtained via enhancement of intermolecular π···π interactions induced successive single-crystal-to-single-crystal transformations, from solvated 1⋅2CH3OH⋅4H2O, to desolvated 1, and its polymorph 1a accompanying electron-transfer. 1⋅2CH3OH⋅4H2O showed thermally-induced reversible intermetallic electron-transfer in mother liquor. No electron-transfer behavior was observed in 1. 1a showed reversible intermetallic electron-transfer upon thermal treatment or alternative irradiation with 808 and 532 nm lasers at cryogenic temperatures. The electron-transfer behaviors significantly change the magnetic and optical properties, providing a strategy to realize different electron-transfer behaviors and switchable functions via π···π interactions manipulated dynamic crystalline transformation.