Syntheses and characterizations of heteroatom-containing open-framework aluminophosphates

Two heteroatom-containing open-framework aluminophosphates, (C(3)H(4)N(2))(2)FeAl(3)P(4)O(16) and (C(3)H(4)N(2))(2)CrAl(3)P(4)O(16) (denoted as MAPO-CJ50, M = Fe, Cr), have been synthesized by using imidazole as the template under solvothermal conditions. The structure of FeAPO-CJ50 is determined by single-crystal X-ray diffraction, and its analogous structure CrAPO-CJ50 is identified by powder X-ray diffraction. The 3-dimensional framework of MAPO-CJ50, constructed by MO(4)N(2) octahedra, AlO(4) tetrahedra, and PO(4) tetrahedra, contains interconnecting 10- and 8-ring channels. Imidazole molecules are coordinated with framework M(3+) ions and interact with each other through π-π stacking interactions in the channels. These two compounds show photoluminescent properties due to ligand-to-metal charge transfer. Magnetic measurements reveal that there are antiferromagnetic interactions between M(3+) ions in the frameworks of FeAPO-CJ50 and CrAPO-CJ50.