[Zn2(HPO3)2(H2PO3)][C3H5N2] and [Zn2(HPO3)3][C4H7N2]2·2H2O: Two new layered zinc phosphites with double 12-membered rings templated by imidazole and 2-methylimidazole

Two new zinc phosphites [Zn2(HPO3)2(H2PO3)][C3H5N2] 1 and [Zn2(HPO3)3][C4H7N2]2·2H2O 2 have been hydrothermally synthesized templated by imidazole and 2-methylimidazole. Single-crystal X-ray diffraction analysis reveals that the two compounds have the similar inorganic framework structures, which both exhibit 2D double layer structures with double 12-membered rings. Due to the different space-filling effect of the guest molecules, the stacking mode of adjacent layers and the arrangement mode of the organic amines are distinct. In 1, the adjacent layers are stacked in an –ABAB– sequence and monoprotonated imidazole molecules sit in the middle of 12MR windows, while in 2, the layers are stacked in an –AAAA– pattern. Monoprotonated 2-methylimidazole molecules occupy two different sites, one inserts into 12MR and the other resides in the interlayer region. Crystal data for 1: triclinic, P-1, image, image, image, image, image, image, image, image; for 2: triclinic, P-1, image, image, image, image, image, image, image, image.