Structural Transformation from Dimerization to Tetramerization of Serine‐Decorated Rare‐Earth‐Incorporated Arsenotungstates Induced by the Usage of Rare‐Earth Salts

Abstract

Three types of serine-decorated rare- earth-containing arsenotungstate [H N(CH ) ] NaH[RE W O (H O) (Ser) (B-α-AsW O ) ]⋅30 H O (RE =Eu , Gd , Tb , Dy , Ho , Er , Tm , Yb , and Y ; 1), [H N(CH ) ] Na RE H [RE W O (H O) (OH) (Ser) (B-α-AsW O ) ]⋅n H O (RE =Tb , x=1, y=2, n=36; RE =Dy , Ho , Er , Yb , Y , x=0, y=0, n=38; RE = Tm , x=1, y=0, n=38; Ser=serine; 2), and [H N(CH ) ] Na RE H [RE W O (H O) (OH) (Ser) (B-α-AsW O ) ]⋅Cl ⋅n H O (RE =Ce , Pr , x=1, y=0, n=65; RE =Nd , Sm , x=0, y=0, n=65; RE =Eu , Gd , x=1, y=2, n=45; 3) were synthesized with the participation of the organic solubilizers dimethylamine hydrochloride and l-serine and were structurally characterized. The use of different amounts of rare-earth salts results in the structural transformation from dimerization to tetramerization of types 1-3. Type 1 is a dimeric sandwich-type assembly of a dual-Ser-participating [RE W O (H O) (Ser) ] entity sandwiched by two [B-α-AsW O ] moieties, whereas types 2 and 3 have a tetrameric square structure formed by four [B-α-AsW O ] moieties that anchor a dual/tetra- Ser-participating [RE W O (H O) (OH) (Ser) ] or [RE W O (H O) (OH) (Ser) ] core. The solid-state luminescence properties and lifetime-decay behaviors of these compounds were investigated. The chromaticity coordinates, dominant wavelengths, color purities, and correlated color temperatures were also calculated.

Preparations, Structures and Luminescence Properties of Penta‐rare‐earth Incorporated Tetravacant Dawson Selenotungstates and Their Ho3+/Tm3+ Co‐doped Derivatives

“…1 D 2 transition of the Tm 3 + ion is seen in the excitation spectrum ( Figure 3h). [11] The lifetime decay curve of 3 was recorded and is well simulated by the second-order exponential equation (Figure 3i), affording τ 1 of 0.93 μs (31.12%), τ 2 of 8.11 μs (68.88%) A 1 of 1305.95 and A 2 of 330.58. Similarly, τ* is calculated as 5.87 μs (Table S1a in the supporting information).…”

“…Thereinto, protonated dimethylamine species serving as counter cations can promote the stability of the whole structure, which is an important factor in the process of the resulting products. [11] The dimeric 1 a polyanion ( Figure 1a) Figure S2 in the supporting information). [11] (4) Å].…”

“…[11] The dimeric 1 a polyanion ( Figure 1a) Figure S2 in the supporting information). [11] (4) Å]. Moreover, O15, O15A, O19 and O19A atoms make up the bottom plane of the bicapped square-pyramidal, O4W atom is located on the vertex position, and bridging O10 and O10A atoms sit on the capped sites ( Figure 1i).…”

Three Types of Mixed Alkali‐Metal‐, Transition‐Metal‐, or Rare‐Earth‐Substituted Sandwich‐Type Arsenotungstates with Supporting Rare‐Earth Pendants

“…The I ( 4 G 5/2 → 6 H 9/2 )/ I ( 4 G 5/2 → 6 H 5/2 ) intensity ratio for 4 of 2.02 indicates that the [Sm1(H 2 O) 8 ] 3+ cation in 4 has a lower symmetry coordination environment, which is consistent with the nine‐coordinate monocapped tetragonal‐antiprismatic geometry of the [Sm1(H 2 O) 8 ] 3+ cation from the single‐crystal X‐ray diffraction analysis. The excitation spectrum of 5 with emission at λ = 642 nm (Figure b) displays six observable peaks at λ = 401, 416, 442, 466, 491, and 503 nm, which are attributed to the 6 H 5/2 → 4 F 7/2 , 6 H 5/2 → 6 P 5/2 , 6 H 5/2 → 4 G 9/2 , 6 H 5/2 → 4 I 13/2 , 6 H 5/2 → 4 I 9/2 , and 6 H 5/2 → 4 G 7/2 transitions, respectively , . The decay curve of 4 obtained with the emission monitored at λ = 642 nm conforms to the second‐order exponential function I = A 1 exp(– t/τ 1 ) + A 2 exp(– t/τ 2 ) (Figure c).…”

Self‐Organization of Ionic Liquid‐Modified Organosilica Hollow Nanospheres and Heteropolyacids: Efficient Preparation of 5‐HMF Under Mild Conditions

“…Heteropolyacids are widely used in catalysis, [26,27] energy storage, [28,29] and materials chemistry. [30,31] Additionally, the heteropolyacids represent a class of green alternatives to traditional mineral acids due to their strong Brønsted acidic nature, high proton mobility and stability. [32] However, the broad utilization of heteropolyacids is still hampered due to their low BET surface areas (1-10 m 2 g À 1 ) and tendency to dissolve in the reaction mixture which makes the separation process highly challenging.…”