From a new trigonal cadmium hexacyanoferrate to a Cd Prussian Blue analogue: single-crystal to single-crystal transformation and C2H2/CO2 separation capability

A newly synthesized coordination polymer, [Cd(DMSO)(H2O)](3)[Fe(CN)(6)](2) (CdHCF-T), based on Cd2+ and Fe(CN)(6)(3-) ions was prepared in a DMSO/H2O mixed solution and crystalized in the trigonal space group P-31c. This novel 3D structure presented an interesting single-crystal to single-crystal transformation when the coordinated DMSO molecules were replaced by H2O, forming a well-known Cd Prussian Blue analogue (Cd-PBA). This occurrence is a rare phenomenon in transition metal hexacyanometallates and may provide a new strategy for obtaining new structures and overcoming the difficulty of growing single crystals of Prussian Blue analogues. Subsequent gas sorption and separation investigations based on the obtained Cd-PBA were also carried out to evaluate its C2H2/CO2 separation capability.

Automated summary

A new coordination polymer, [Cd(DMSO)(H2O)](3)[Fe(CN)(6)](2) (CdHCF-T), with a trigonal P-31c crystal structure, was synthesized in a DMSO/H2O mixed solution and underwent a single-crystal to single-crystal transformation to form a Cd Prussian Blue analogue (Cd-PBA) by replacing the coordinated DMSO molecules with H2O. This rare phenomenon in transition metal hexacyanometallates could offer a new strategy for obtaining new structures and overcoming the difficulty of growing single crystals of Prussian Blue analogues. Gas sorption and separation studies on the obtained Cd-PBA were conducted to evaluate its C2H2/CO2 separation capability.