Hydrothermal synthesis and characterization of a new organic templated metallophosphate [Zn(H2PO4)2(HPO4)][C7H17N2]

A new organic templated metallophosphate, [Zn(H2PO4)2(HPO4)][C7H17N2] (denoted in the following ZnP-AMEP), has been synthesized hydrothermally using 2-aminomethyl,1-ethylpyrrolidine (AMEP) as a structure-directing agent. The structure, determined by single crystal X-ray diffraction, exhibits a parallel arrangement (along the [11¯0] direction) of infinite chains, built from (Zn2P2O12) four-membered rings sharing ZnO4 tetrahedra, interconnected together by strong hydrogen bonds to form a sheet-like architecture and with chains of (H2PO4)nn- extending along [1 0 0] at y = 1/2 to form a 3D anionic network. To the best of our knowledge, the compound ZnP-AMEP represents the first organic templated metallophosphate in which the four-membered rings interact with chains of dihydrogenophosphate. Intra-chain and inter-chain P–OH⋯O hydrogen bonds help to establish the crystal packing and form apertures, wherein the amine molecules are located. Similarities and differences with other organic templated metallophosphates are briefly discussed for the title compound. Ab initio calculations allow the attribution of phosphorus and carbon solid-state NMR signals to the independent crystallographic sites and to the various atoms of the organic groups. Additional characterizations of the compound have also been performed by IR spectroscopy and TG–DTA analyses.

Graphical abstractZnO+3H3PO4+C7H15N2→[Zn(H2PO4)2(HPO4)][C7N2H17]+H2OZnO+3H3PO4+C7H15N2→[Zn(H2PO4)2(HPO4)][C7N2H17]+H2OFigure optionsDownload full-size imageDownload as PowerPoint slide