Two Ce³⁺-Substituted Selenotungstates Regulated by N,N-Dimethylethanolamine and Dimethylamine Hydrochloride

Abstract

Two multi-Ce3+-substituted selenotungstates (STs), [HDMEA]­[H2N­(CH3)2]4­H3Na4­[Ce2(H2O)6­(DMEA)­W4O9­(α-SeW9O33)3]·26H2O (1) and [H2N­(CH3)2]10­H4Na10­[Ce2W4O9(H2O)7­(α-SeW9O33)3]2·63H2O (2), were prepared by the one-pot approach of sodium tungstate, sodium selenite, and lanthanide nitrate in an acidic water solution in the presence of N,N-dimethylethanolamine (DMEA) or dimethylamine hydrochloride (DMAHC). 1 was obained in the presence of DMEA, whereas 2 was synthesized in the presence of DMAHC. The trimeric polyoxoanion of 1 contains an unusual V-shaped [Se3W29O103]20– group embracing a prominent heterometal oxide fragment, [Ce2(H2O)6(DMEA)­W2O5]8+, and the hexameric polyoxoanion of 2 is constructed from two equivalent trimeric [Ce2W4O9(H2O)7(SeW9O33)3]2 24– subunits through two −O–W–O–Ce–O– linkages. The most worthy of attention is that the polyoxoanion of 1 can be approximatively viewed as a half of the polyoxoanion of 2 because of the coordination and blocking effect of DMEA. The stability of 1 and 2 in different water pH values was studied by electrospray ionization mass spectroscopy (ESI-MS), and the results manifest that 1 and 2 are stable in pH = 3.5–7.5 and 3.5–7.0, respectively. The oxidation reactions of aromatic sulfides catalyzed by H2O2 were studied when 1 or 2 worked as a catalyst, and experimental results reveal that 1 or 2 can serve as available catalysts for the oxidation of aromatic sulfides under mild conditions.

Self-Assembly Hydrothermal Synthesis of Silverton-Type Polyoxometalate-Based Photocatalysts for Enhanced Degradation

“…The XRD structural analysis 49 revealed that the CoWOH crystallizes in the cubic system with the space group Im3̅ . The refinement details are summarized in Table S1.…”

Synthesis of Two Monomeric Tri‐Substituted γ*‐Dawson‐Type Polyoxotungstates

“…The IR spectrum of both 1 and 2 show the characteristic vibration patterns resulting from Dawson‐type polyoxometalates in the range of 1100–700 cm –1 (Figure S2, Supporting Information), and the characteristic bands at around 1088 cm –1 can be attributed to the feature of ν(P–O); compared to the IR spectrum of sandwich‐type {M 4 (P 2 W 15 ) 2 } (M = Co, Ni), the ν(P–O) trend to high‐wavenumber shift, which is possibly relate to metal M interacts more strongly with the oxygen atom of the PO 4 tetrahedron . The bands at 1011 cm –1 are assigned to the ν(W=O), the bands at 915 and 946 cm –1 are characteristics of v(M–O b –M) (M = Co, Ni or W), at lower wavenumbers than for the parent saturated Dawson‐type phosphotungstate; the bands at 796 and 715 cm –1 are attributed to the v(M–O c –M) (M = Co, Ni or W).…”

Roles of Organic Fragments in Redirecting Crystal/Molecular Structures of Inorganic–Organic Hybrids Based on Lacunary Keggin-Type Polyoxometalates

“…In some cases, organic ligands not only do not contribute to the increasing nuclearity of a structure but also acts vice versa. A notable example is the work of Li et al Because of the blocking effect of DMEA, the trimeric polyoxoanion [Ce 2 (H 2 O) 6 (DMEA)W 4 O 9 ( α -SeW 9 O 33 ) 3 ] with an infrequent V-shaped [Se 3 W 29 O 103 ] 20− group was obtained ( Figure 3 a), whereas in the presence of DMAHC, the hexameric polyoxoanion [Ce 2 W 4 O 9 (H 2 O) 7 ( α -SeW 9 O 33 ) 3 ] 2 24− was constructed from two equivalent trimeric subunits through two −O−W−O−Ce−O− connections ( Figure 3 b) [ 141 ].…”

“… ( a ) Trimeric [Ce 2 (H 2 O) 6 (DMEA)W 4 O 9 (α-SeW 9 O 33 ) 3 ] cluster. ( b ) Hexameric [Ce 2 W 4 O 9 (H 2 O) 7 (α-SeW 9 O 33 ) 3 ] 2 polyoxoanion structure [ 141 ]. …”