Solvothermal synthesis of new open-framework metal phosphites with structure-directing agents generated in situ

By using amide molecules and a urea derivative as the source of structure-directing agents (SDAs), three open-framework metal phosphites, (CH3NH3)2·[Be3(HPO3)4] (1), (CH3CH2NH3)2·[Be3(HPO3)4] (2), and [(CH3)2NH2]1.5·(H3O)0.5·[Al4(HPO3)7(H2O)3]·(H2O)0.5 (3), have been synthesized under solvothermal conditions. Compound 1 has left- and right-handed helical channels running along the [001] directions. Compound 2 possesses zigzag 12-ring channels running along the [001] direction. Compound 3 contains multidirectional 12-ring channels running along the [100], [010], and [110] directions. It is noteworthy that the direct use of methylamine, ethylamine and dimethylamine as SDAs can't produce corresponding single crystals of compounds 1–3, demonstrating the slow release of amines from amide molecules and urea derivative is a key process for the crystal growth.

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► Three open-framework metal phosphites have been synthesized under solvothermal conditions.
► Amide molecules and one urea derivative have been used as the sources of structure-directing agents.
► The slow release of amines is a key process in the structural formation.