The use of Tetracyanozincate(II) in the preparation of supramolecular coordination polymers

Several coordination polymers using K2[Zn(CN)4] as starting material have been prepared. [Zn(CN)4]2- acts as a building block and source of free cyanide due to lability. A Cu(I)/Cu(II)/Zn(II) mixed-valent [Cu(en)2][Zn(NC)4(CuCN)2] polymer (en= ethylenediamine), which has a 2-D layer structure with six structurally inequivalent cyanides in four bonding modes, was characterized. By using mixed chlorinated solvent/aquous layers, complexes with solvent molecules incorporated were afforded: [Cu(en)2]0.5[CuZn(NC)4][C6H5Cl]n and [Cu(en)2]0.5[CuZn(NC)4](CHCl3). Both structures contain a 3-D diamonded array. Due to thermal motion and disorder of solvent molecules, further details were not clearly identified. Three anhydrous microporous cyanometallate complexes and their non-porous hydrates were prepared: KCoFe(CN)6 and KZnFe(CN)6 with Prussian Blue type structure and CoZn(CN)4. All three anhydrous complexes exhibit hydrogen affinity at cryogenic conditions. Their H2 and N2 adsorption isotherms are analyzed using different adsorption models, showing surface areas and adsorption capacities ranging from 399 to 615 m2/g, and 0.77 to 1.01 wt% at 77K/1atm respectively.