Na(H3NCH2CH2NH3)0.5[Co(C2O4)(HPO4)]: A novel phosphoxalate open-framework compound incorporating both an alkali cation and an organic template in the structural tunnels

The first open-framework metal phosphoxalate compound containing both an organic and an inorganic template in the same structure is reported. Na(H3N+CH2CH2N+H3)0.5[Co(C2O4)(HPO4)] (1) was synthesized hydrothermally via a direct metathesis reaction using the sodium salts of oxalate and phosphate in the presence of cobalt chloride and ethylenediamine dihydrochloride. The structure of 1 consists of a 3D framework built from the [Co(C2O4)]n layers connected by HPO42− group bridging two different cobalt centers between the adjacent layers. A major and a minor structural tunnels are created and occupied by the Na+ and H3N+CH2CH2NH32+ ions, respectively, in the same structure. Single-crystal X-ray crystallographic data for 1 are: monoclinic, P21/c, a=5.8189(6), b=10.235(1), c=13.066(1) Å, β=96.671(2)°, Z=4, V=772.9(1) Å3, R=3.95% and Rw=6.37%.