Gradual Two-step Spin Crossover Behavior of Binuclear Iron(III) Complex Bridged by <i>trans</i>-1,2-Bis(4-pyridyl)ethylene

Abstract

Abstract A binuclear iron(III) complex bridged by trans-1,2-bis(4-pyridyl)ethylene, [LFeIII(vibpy)FeIIIL](BPh4)2, showed a gradual two-step spin crossover behavior, where H2L is bis(3-methoxysalicylideneaminopropyl)methylamine and BPh4− is tetraphenylborate. The single-crystal X-ray analysis at the intermediate state revealed that one of the two FeIII ions of the binuclear complex is in the high-spin (HS) state and the other is in the low-spin (LS) state. The HS and LS sites independently form layers and these HS and LS layers alternately stack.