Site‐Specific Iron Substitution in STA‐28, a Large Pore Aluminophosphate Zeotype Prepared by Using 1,10‐Phenanthrolines as Framework‐Bound Templates

Abstract

An AlPO4 zeotype has been prepared using the aromatic diamine 1,10‐phenanthroline and some of its methylated analogues as templates. In each case the two template N atoms bind to a specific framework Al site to expand its coordination to the unusual octahedral AlO4N2 environment. Furthermore, using this framework‐bound template, Fe atoms can be included selectively at this site in the framework by direct synthesis, as confirmed by annular dark field scanning transmission electron microscopy and Rietveld refinement. Calcination removes the organic molecules to give large pore framework solids, with BET surface areas up to 540 m2 g−1 and two perpendicular sets of channels that intersect to give pore space connected by 12‐ring openings along all crystallographic directions.

Thermal Dehydrofluorination of GaPO-34 Revealed by NMR Crystallography

“…It can be seen that Ga1 is pentacoordinate, whereas Ga2 and Ga3 remain tetrahedral, which is consistent with the approximate Ga IV :Ga V ratio observed experimentally. The pentacoordinate Ga1 site with a GaO4N environment containing a direct bond to the deprotonated SDA is a motif rarely observed in gallophosphate-like materials 46,47 (and never in a fully condensed 3D GaPO4 framework material, although there are a small number of fully condensed AlPOs and GaPOs that do contain similar interactions, giving rise to octahedral AlO4(OH)N, 48 AlO4N2, 49 and GaO4(OH)N 50 coordination environments). The Ga-N bond distance is 2.04 Å, which is comparable to the 2.02-2.18 Å observed in the literature.…”