Rare Examples of Amine-Templated Organophosphonate Open-Framework Compounds: Combined Role of Metal and Amine for Structure Building

Abstract

By introduction of 2-methyl-1,5-diaminopentane (DAP) and 1,4-diaminobutane (DAB) as templated ions, three new amine-templated organophosphonate open-framework compounds [H2DAP][Zn6(Hhedp)2(hedp)2]·4H2O, I, [H2DAB][Zn6(Hhedp)2(hedp)2]·4H2O, II, and [H2DAB][Zn3(hedp)2]·2H2O, III, have been synthesized, structurally analyzed, and characterized for the first time. Both compounds I and II have analogous 2-D sheet structure connecting through metal and diphosphonates (1-hydroxyethane-1,1-diphosphonic acid), while the templated amines are different in the framework. Compound III consists of Zn ions and diphosphonate ligands with templated DAB, forming three-dimensional framework with interconnected 4-T, 8-T, and 12-T ring channels. To the best of our knowledge, such structural modifications with coordination variation of metal ions applying the same amine have never been reported in the organophosphonate family. The presence of mixed metal as well as different aliphatic amines plays a crucial role for the struct...