Layered Rare Earth Hydroxides: Structural Aspects and Photoluminescence Properties

Hydrothermal crystallization of a Ln2(OH)4SO4·nH2O layered compound for a wide range of Ln (Ln = La–Dy), thermolysis, and facile transformation into oxysulfate and oxysulfide phosphors

“…The general chemical formula of layered rare-earth hydroxides (LRHs) can be expressed as Ln 2 (OH) 6Àm (A xÀ ) m/x $nH 2 O (Ln: trivalent rare-earth ions; A: guest anion; 1.0 # m # 2.0), 1,2 with Ln 2 (OH) 5 (A xÀ ) 1/x $nH 2 O (m ¼ 1), termed as the 251 phase, and Ln 2 (OH) 4 (A xÀ ) 2/x $nH 2 O (m ¼ 2), termed as the 241 phase, being two important groups of the family. The 251 phase has drawn signicant attention since its rst report in 2006 and is nding potential applications in various elds including pollutant trapping, rechargeable batteries, drug delivery, heterogeneous catalysis, and microelectronics.…”

Specific lift-up behaviour of acetate-intercalated layered yttrium hydroxide interlayer in water: application for heterogeneous Brønsted base catalysts toward Knoevenagel reactions

“…According to the Hann and Lapworth mechanism, 59 Knoevenagel condensation should be applied to the secondorder kinetic expression. Considering a second-order relationship, the rate equation is r = k• [1]• [2], where r is the reaction rate, k is the rate constant, and [1] or [2] are concentrations of 1 or 2, respectively. If the concentrations of 1 and 2 are the same, the integrated rate equation is:…”

“…As a new type of anionic layered compound, layered rareearth hydroxides (LRHs) are receiving much attention, due to their unique characteristics combined with their host-guest properties and rare-earth cations. [1][2][3][4] In contrast to the famous anion-exchangeable layered double hydroxides (LDHs), 5 [M 2+ 1−x M 3+ x (OH) 2 ][A x/q q− •mH 2 O] (x and A q− : the ratio of M 3+ / (M 2+ + M 3+ ) and the interlayer anion with valence q, respectively), the general formula of LRHs is [Ln 4 (OH) 10 (H 2 -O) 4 ] n A n , where Ln is a rare-earth metal cation. The cationic layer of LRHs, [Ln 4 (OH) 10 (H 2 O) 4 ] 2+ , contains two kinds of coordination polyhedra, such as a dodecahedron (8-coordination) and a monocapped square antiprism (9-coordination), linked through μ 3 -hydroxy groups.…”