Structural
Assembly from Phosphate to Germanophosphate by Applying Germanate
as a Binder
- Publication date
- Publisher
Abstract
Structural assembly from phosphate
to germanophosphate by applying germanate as a binder has been achieved.
Two isotypic porous compounds, K<sub>3</sub>[M<sup>II</sup><sub>4</sub>(HPO<sub>4</sub>)<sub>2</sub>][Ge<sub>2</sub>O(OH)(PO<sub>4</sub>)<sub>4</sub>]·<i>x</i>H<sub>2</sub>O (<i>M</i><sup>II</sup> = Fe, Cd; <i>x</i> = 2 for Fe and 3 for Cd,
denoted as <b>KFeGePO-1</b> and <b>KCdGePO-1</b>, respectively),
contain a known transition-metal phosphate (TMPO) layer, <sub>∞</sub><sup>2</sup>{[<i>M</i><sub>2</sub>(HPO<sub>4</sub>)<sub>3</sub>]<sup>2–</sup>}, which is built from chains of trans-edge-sharing <i>M</i>O<sub>6</sub> octahedra bridged by <i>M</i>O<sub>5</sub> trigonal bipyramids that were further linked and decorated by phosphate
tetrahedra. The layers are bound by infinite chains of GeO<sub>5</sub>(OH) octahedra, resulting in a 3D open-framework structure with 1D
12-ring channels that are occupied by K<sup>+</sup> ions and water
molecules. The curvature of the TMPO layers and shape of the 12-ring
windows can be tuned by the transition metals because of their Jahn–Teller
effect
