Isostructural compartmentalized spin-crossover coordination polymers for gas confinement

Abstract

Here we present two Fe^II coordination polymers that possess discrete compartments suitable for CO₂ physisorption despite the lack of permanent channels. The two crystalline materials, of general formula [Fe(btzbp)₃](X)₂ (X = ClO₄ or BF₄), present voids of ca. 250 ų, which each can accommodate up to two CO₂ molecules. The abrupt spin transition can be modified upon CO₂ sorption, and different magnetic behaviour is observed depending on the number of molecules sorbed.