Syntheses and Crystal Structures of the Bromide-derivatized Lanthanoid(III) Ortho-Oxomolybdates(VI) LnBr[MoO₄] (Ln = Pr, Nd, Sm, Gd– Lu)

Abstract

The lanthanoid(III) bromide ortho-oxomolybdates(VI) LnBr [MoO 4 ] (Ln = Pr, Nd, Sm, Gd -Lu) crystallize triclinically in the space group P1 (a = 686 -689, b = 713 -741, c = 1066 -1121 pm, α = 103 -106, β = 107 -108, γ = 92 -95 • ) with Z = 4. The crystal structure contains two crystallographically distinguishable Ln 3+ cations, each one with a coordination number of seven plus one. (Ln1) 3+ is surrounded by three bromide and four plus one oxide anions, while for (Ln2) 3+ just one bromide and six plus one oxide anions belong to the coordination sphere. Considering the smallest lanthanoids, however, the distances to the farthest anions increase so much that their contribution to the coordination spheres becomes negligible in both cases. The polyhedra around (Ln1) 3+ are connected to each other via common edges, which consist of two crystallographically identical Br − anions (Br1).

Heteroanionic LaBrVIO4 (VI = Mo, W): Excellence in Both Nonlinear Optical Properties and Photoluminescent Properties

“…The high-temperature solid-state method was employed as the major technique to grow crystals of REBrVIO 4 (RE = Y and La–Lu; VI = Mo and W), ,,, where REBr 3 was used as reactants and flux. Small amounts of impurity were detected after the reaction process of LaBrMoO 4 .…”

“…Based on the ICSD 2022 database, there are twenty-three compounds reported within the REBrVIO 4 (RE = Y and La–Lu; VI = Mo and W) system (Table S4). ,,, A few interesting observations: (1) there are two structure models reported: acentric Pc (two compounds) and centrosymmetric P 1̅(twenty-one compounds); (2) there are fourteen Mo-containing compounds studied versus only nine W-contained compounds. All W-containing compounds crystallize in the centrosymmetric P 1̅ structure model; (3) all W-containing compounds constitute rare earth elements from Gd to Lu with no light rare earth elements involved, such as La and Ce, except Y. LaBrWO 4 is the first acentric W-contained compound of the REBrVIO 4 (RE = Y and La–Lu; VI = Mo and W) system, which exhibits excellent nonlinear optical properties and photoluminescent properties (vide infra).…”

“…LaBrWO 4 is isostructural to LaBrMoO 4 , which belongs to the REBrVIO 4 (RE = Y and La−Lu; VI = Mo and W) system. 54,55,60,79 LaBrWO 4 is discovered for the first time. The rare earth doping did not change the crystal structure (Table 1).…”

“…Based on the ICSD 2022 database, there are twenty-three compounds reported within the REBrVIO 4 (RE = Y and La−Lu; VI = Mo and W) system (Table S4). 54,55,60,79 A few interesting observations: (1) there are two structure 4)°. Because β is close to 90°, orthorhombic symmetry was also considered during lattice and space group determination.…”

Blue Excitement: The Lanthanide(III) Chloride Oxidomolybdates(VI) Ln3Cl3[MoO6] (Ln = La, Pr, and Nd) and Their Spectroscopic Properties

“…They experienced a brief renaissance in the early 1980s when the group around Brixner thorougly investigated several chloride oxidotungstates of lanthanum − and gadolinium, including remarks about their availability throughout the lanthanoid series. Halide derivatives of rare-earth metal oxidomolybdates on the other hand remained unknown until 2008, and since then, several articles about the structure and properties of the LnX­[MoO 4 ] families (Ln = lanthanoid; X = fluoride, chloride, and bromide) have been published, − with all of these compounds comprising noncondensed [MoO 4 ] 2– tetrahedra. Except for the fluoride derivatives, all rare-earth metal halide molybdates also have their counterparts with similar structural elements in the realm of the tungstates; however, no molybdenum analogues of the Ln 3 Cl 3 [WO 6 ] (Ln = La–Nd and Sm–Tb) representatives ,,,, have been presented in the literature (except for a short annotation by Brixner).…”