Isostructural compartmentalized spin-crossover coordination polymers for gas confinement

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 angstrom(3), 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.