The research on electron transfer coupled spin transition regulating the valence state and spin state transition of metal ions is promising and challenging. Herein, we report a cyano-bridged {(Fe2Fe2II)-Fe-III} molecular square complex, {[Fe(Tp)(CN)(3)](2) [Fe(bnbpen)](2)}(ClO4)(2)8CH(3)OH (18CH(3)OH, bnbpen = N,N '-bis-(2-naphthylmethyl)-N,N '-bis(2-picolayl)-ethylenediamine), and its free of solvents form (1). Combined single-crystal X-ray diffraction, temperature-dependent infrared (IR) spectra, magnetic measurements, and M & ouml;ssbauer spectra reveal that 18CH(3)OH and 1 exhibit reversib...
