Four-Step Spin Crossover in a New Cyano-Bridged Iron-Silver Coordination Polymer

Chemistry. 2022 Aug 4;28(44):e202200924. doi: 10.1002/chem.202200924. Epub 2022 Jun 16.

Abstract

Spin-crossover complexes with multistep transitions attract much attention due to their potential applications as multi-switches and for data storage. A four-step spin crossover is observed in the new iron(II)-based cyanometallic guest-free framework compound Fe(2-ethoxypyrazine)2 {Ag(CN)2 }2 during the transition from the low-spin to the high-spin state. A reverse process occurs in three steps. Crystallographic studies reveal an associated stepwise evolution of the crystal structures. Multiple transitions in the reported complex originate from distinct FeII sites which exist due to the packing of the ligand with a bulky substituent.

Keywords: Hofmann clathrates analogues; iron(II); multistep transitions; spin crossover; substituted pyrazine.