title: New layered rare-earth hydroxides with anion-exchange properties.
abstract: We report the synthesis of a new series of layered hydroxides based on rare-earth elements with a composition of RE(OH)2.5Cl(0.5).0.8 H2O (RE: Eu, Tb, etc.) through the homogeneous precipitation of RECl3.x H2O with hexamethylenetetramine (HMT). Rietveld analysis combined with direct methods revealed an orthorhombic layered structure comprising a positively charged layer of [RE(OH)2.5-(H2O)0.8]0.5+ and interlayer Cl- ions. The Cl- ions were readily exchangeable for various anions (NO3-, SO4(2-), dodecylsulfonate, etc.) at ambient temperature. Photoluminescence studies showed that the compounds display typical RE3+ 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.
authors.affiliation: International Center for Materials Nanoarchitectonics and Nanoscale Materials Center, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
authors.forename: Fengxia
authors.initials: F
authors.lastname: Geng
authors.forename: Hao
authors.initials: H
authors.lastname: Xin
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Matsushita
authors.forename: Renzhi
authors.initials: R
authors.lastname: Ma
authors.forename: Masahiko
authors.initials: M
authors.lastname: Tanaka
authors.forename: Fujio
authors.initials: F
authors.lastname: Izumi
authors.forename: Nobuo
authors.initials: N
authors.lastname: Iyi
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Sasaki