Synthesis, structure and characterization of two new open-framework gallium phosphite-oxalates of varying dimensionality

•Using N, N-dimethyl-piperazine as structure directing agent, two new gallium phosphite-oxalates have been synthesized under solvothermal and hydrothermal conditions, respectively.•The same second building unit (SBU) is displayed in both compounds.•Compound I shows 2D layered structure with 8-MR windows while compound II presents 3D open-framework with 8-MR channels.•The solvent plays an important role on the formation of microporous compounds.

Using N, N-dimethyl-piperazine as structure directing agent, two new gallium phosphite-oxalates [Ga2(HPO3)2(H2PO3)2(C2O4)](C6N2H16) (I) and [Ga2(HPO3)2(H2PO3)(C2O4)](C6N2H16)0.5 (II) have been synthesized under solvothermal and hydrothermal conditions, respectively and further characterized by powder X-ray diffraction, IR spectroscopy, TGA, ICP-AES and elemental analyses. Single crystal X-ray diffraction reveals that the striking feature of I and II is that they possess the same second building unit (SBU) Ga2P2 constructed from two GaO6 octahedra and two [HPO32−] pseudo-pyramids sharing oxygen atoms. However, due to the different connecting fashions of SBUs, [C2O42−] groups and [H2PO3−] pseudo-pyramids, the final frameworks of them are distinctly different. Compound I shows 2D layered structures with 8-membered ring (8-MR) windows in the ab plane while compound II presents a 3D open-framework with 8-MR channels along the b axis.

Graphical abstractUsing N, N-dimethyl-piperazine as structure directing agent, two new gallium phosphite-oxalates I showing 2D layered structure and II presenting 3D open-framework have been synthesized under solvothermal and hydrothermal conditions, respectively.Figure optionsDownload full-size imageDownload as PowerPoint slide