New Layered Rare‐Earth Hydroxides with Anion‐Exchange Properties

Abstract

Abstract We report the synthesis of a new series of layered hydroxides based on rare‐earth elements with a composition of RE(OH) 2.5 Cl 0.5 ⋅0.8 H 2 O (RE: Eu, Tb, etc.) through the homogeneous precipitation of RECl 3 ⋅ x H 2 O with hexamethylenetetramine (HMT). Rietveld analysis combined with direct methods revealed an orthorhombic layered structure comprising a positively charged layer of [RE(OH) 2.5 (H 2 O) 0.8 ] 0.5+ and interlayer Cl − ions. The Cl − ions were readily exchangeable for various anions (NO 3 − , SO 4 2− , dodecylsulfonate, etc.) at ambient temperature. Photoluminescence studies showed that the compounds display typical RE 3+ emission. With rare‐earth‐based host layers and tunable interlayer guests, the new compounds may be of interest for optoelectronic, magnetic, catalytic, and biomedical materials.