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Two new cyano-bridged mixed-valence {Fe III 2 (μ-CN) 4 Fe II 2 } clusters, {[(Tp)Fe III (CN) 3 ] 2 [Fe II (Py 2 N 2 )] 2 }·(ClO 4 ) 2 ·MeCN·Et 2 O ( 1 ·MeCN·Et 2 O), its solvent-free form ( 1 ), and {[(Tp)Fe III (CN) 3 ] 2 [Fe II (Me 2 Py 2 N 2 )] 2 }·(ClO 4 ) 2 ·5MeOH ( 2 ·5MeOH), were obtained [Tp = hydrotris(pyrazol-1-yl)borate; N , N '-bis(2-pyridylmethyl)- N , N '-bis(4-X-benzyl)-1,2-ethanediamine, Py 2 N 2 , X = H; Me 2 Py 2 N 2 , X = Me]. Complexes 1 and 2 ·5MeOH exhibit gradual thermally induced two-step spin-crossover behavior (SCO) at two Fe II metal centers, and the transformation of high-spin (HS) to low-spin (LS) Fe II ions with temperature was confirmed by a combination of X-ray crystallography, variable-temperature Fourier transform infrared, variable-temperature magnetic susceptibility, and 57 Fe Mössbauer spectroscopy. Moreover, complexes 1 ·MeCN·Et 2 O and 1 exhibit a reversible single-crystal-to-single-crystal transformation, and complex 1 undergoes two-step SCO behavior with T 1/2 = 178 and 93 K accompanied by symmetry breaking in the structure.