Structure refinement of (NH4)3Al2(PO4)3 prepared by ionothermal synthesis in phospho-nium based ionic liquids - a redetermination.

ABSTRACT: After crystallization during ionothermal syntheses in phospho-nium-containing ionic liquids, the structure of (NH4)3Al2(PO4)3 [tri-ammonium dialuminum tris-(phosphate)] was refined on the basis of powder X-ray diffraction data from a synchrotron source. (NH4)3Al2(PO4)3 is a member of the structural family with formula A 3Al2(PO4)3, where A is a group 1 element, and of which the NH4, K, and Rb forms were previously known. The NH4 form is isostructural with the K form, and was previously solved from single-crystal X-ray data when the material (SIZ-2) crystallized from a choline-containing eutectic mixture [Cooper et al. (2004 ?). Nature, 430, 1012-1017]. Our independent refinement incorporates NH4 groups and shows that these NH4 groups are hydrogen bonded to framework O atoms present in rings containing 12 T sites in a channel along the c-axis direction. We describe structural details of (NH4)3Al2(PO4)3 and discuss differences with respect to isostructural forms.

SUBMITTER: Nicholas CP 

PROVIDER: S-EPMC6895951 | biostudies-literature | 2019 Dec

REPOSITORIES: biostudies-literature