Synthesis and Crystal Structures of New Lanthanide Hydroxyhalide Anion Exchange Materials, Ln₂(OH)₅X·1.5H₂O (X = Cl, Br; Ln = Y, Dy, Er, Yb)

Abstract

A family of layered lanthanide hydroxyhalide intercalation hosts, Ln2(OH)5X·1.5H2O (X = Cl, Br; Ln = Y, Dy, Er, Yb), has been synthesized under hydrothermal conditions and their crystal structure determined. These are the first structures for the m = 1 members of the Ln2(OH)6−m (A) m ·nH2O family of intercalation hosts to be determined. Reaction mixtures with Ln = Yb always yield a biphasic product which adopts an orthorhombic or monoclinic crystal structure. In both cases the layer composition is [Yb2(OH)5(H2O)1.5]+ and the Yb is eight or nine coordinated to bridging hydroxide anions and coordinated water molecules. Charge balancing halide anions are located in the interlayer gallery. The orthorhombic structure is adopted by the other chloride host lattices and the monoclinic one by Y2(OH)5Br·1.5H2O. These materials have been shown to undergo facile room temperature anion exchange reactions with a range of organic dicarboxylates.

Immobilization, Trapping, and Anion Exchange of Perrhenate Ion Using Copper-Based Tripodal Complexes

“…These substances comprise an isostructural class of pure inorganic materials capable of exchanging interlamellar counter anions with other anions of interest. [18][19][20] Metal-organic frameworks with extended cationic networks and guest anions are also potential candidates for anion exchange and trapping. 6,[21][22][23][24] In the foregoing examples, the anions are typically bound through weak electrostatic and/or hydrogen bonding interactions.…”

Synthesis and Photoluminescence of Colloidal Solution Containing Layered Rare-earth Hydroxide Nanosheets

“…Instead, the trivalent rare-earth cations in LRHs occupy the eight-coordinated and the nine-coordinated sites formed by the intralayer OH groups and the interlayer water molecules (Figure 1(b)). 19,22,23 Nevertheless, the structures of LDHs and LRHs are quite similar to each other. The OH groups in the layer of both structures are shared by three polyhedral cations and their hydrogen atoms are directed to the interlayer space.…”

“…Recently, a series of layered compounds consisting of pure cationic rare-earth hydroxide layers have been reported by several authors [19][20][21][22][23] and briefly reviewed. 24 This class of compounds, called the layered rare-earth hydroxides (LRHs), is represented by the general formula RE 2 (OH) 5 X·nH 2 O where X is the organic or inorganic interlayer anions.…”

Recent progress in layered rare-earth hydroxide (LRH) and its application in luminescence

“…Ln 2 (OH) 5 (A x ) 1/x ·nH 2 O (m = 1, n = 1-2, and typically n  1.5; termed as the 251-LRH phase) [5][6][7] and Ln 2 (OH) 4 (A x ) 2/x ·nH 2 O (m = 2, n = 0-2; 241-LRH phase) [8,9] are two important groups of the LRHs family. The anions (such as NO 3  , Cl  , and Br  ) in the 251-LRH phase of n  1.5 frequently exist in the interlayer gallery as free ones (not coordinated to the Ln 3+ center) and thus exhibit facile exchange with a wide range of carboxylate and sulfonate anions [10][11][12][13][14][15]. Therefore, the 251-LRHs may potentially be exfoliated into single-layer nanosheets of significantly two-dimensional morphologies for the further construction of various nanostructures, particularly highly transparent functional films.…”

“…This review article summarizes the recent achievements attained in the fascinating field of LRHs, including controlled crystallization, structural and morphological features, anion exchange and exfoliation, and application in phosphors and transparent films. 2 (x = 2), is mainly located in the interlayer space to support the layers, and the loss of coordinated water molecules will result in an abrupt layer contraction [10][11][12][13][14][15]. The hydration number tends to decrease with increasing atomic number for the chloride family (orthorhombic structure) while increase for the nitrate analogue (monoclinic structure) [6,11].…”