Effects of Both Methyl and Pyrimidine Groups in Fe–Ag Spin-Crossover Hofmann-Type Complex {Fe(4-Methylpyrimidine)<sub>2</sub>[Ag(CN)<sub>2</sub>]<sub>2</sub>}
Kosuke Kitase, Daisuke Akahoshi, Takafumi Kitazawa
Abstract
The spin-crossover (SCO) phenomenon is an active area of research. This paper describes the synthesis of an Fe–Ag Hofmann-type complex, {Fe(4-methylpyrimidine)2[Ag(CN)2]2}, which demonstrates a one-step SCO and single-layer Hofmann-type structure with Ag–N interactions and no Ag–Ag interactions, which is strikingly different from the previously synthesized complex {Fe(4-methylpyrimidine)2[Au(CN)2]2} that contains Au–Au interactions and no Au–N interactions. This difference can be explained in terms of the lack of relativistic effect in the Ag atoms and the different cooperative effects caused by their different structures. A scan-rate-dependent hysteresis is observed using magnetic measurement whereas not using 57Fe Mössbauer spectroscopy, suggesting that the spin transition is relatively slow.