scispace - formally typeset
Search or ask a question
Topic

Polyoxometalate

About: Polyoxometalate is a research topic. Over the lifetime, 3493 publications have been published within this topic receiving 94123 citations. The topic is also known as: POM.


Papers
More filters
Journal ArticleDOI
TL;DR: A new chiral derivative of the known DAMS(+) molecules, named here CHIDAMS(+), has therefore been synthesized in order to force the crystallization of the hybrid ionic salts in noncentrosymmetric space groups.
Abstract: The synthesis of nonlinear optical (NLO) active salts with stilbazolium derivatives and polyoxometalate (POM) counterions has been investigated. With known nonchiral stilbazolium derivatives, such as MOMS(+), compounds with centrosymmetric structures have been isolated, like for instance the centrosymmetric salt (MOMS)(4)[Mo(8)O(26)] (1), synthesized under hydrothermal conditions. A new chiral derivative of the known DAMS(+) molecules, named here CHIDAMS(+), has therefore been synthesized in order to force the crystallization of the hybrid ionic salts in noncentrosymmetric space groups. The CHIDAMS(+) cation has been crystallized under two polymorphic PF(6)(-) salts, (CHIDAMS)PF(6) (2a and 2b), and its reactivity with various POMs has been investigated. The ionic salt (CHIDAMS)(2)[Mo(5)O(13)(OEt)(4)(NO){Na(H(2)O)(0.5)(DMF)(0.5)}] (4) crystallizes in the noncentrosymmetric P2(1) group, but the push-pull axis of the CHIDAMS(+) cations adopts a quasi-antiparallel alignment. The ionic salt (CHIDAMS)(3)[PW(12)O(40)].2DMF (5) associating three CHIDAMS(+) cations and a PW(12)O(40)(3-) Keggin anion crystallizes also in the P2(1) space group, but the disposition of the cations in the solid state is far more favorable. Diffuse reflectance experiments have evidenced a charge transfer between the organic and inorganic components in 5, and Kurtz-Perry experiments show that this salt exhibits a second harmonic generation efficiency more than 10 times higher than those of the PF(6)(-) salts 2a and 2b, the hybrid salt 4, and all of the other NLO active POM molecular materials reported in the literature.

67 citations

Journal ArticleDOI
TL;DR: The catalyst showed distinctive lipophiloselectivity, that is selectivity as a function of the lipophilic nature of a reaction substrate, proportional to the relative partition coefficient (1-octanol/water) of the substrates.
Abstract: A cross-linked polyethyleneimine polymer containing the [ZnWZn2(H2O)2(ZnW9O34)2]12- polyoxometalate was prepared from branched polyethyleneimine (Mw = 600), the polyoxometalate, and a n-octylamine-epichlorohydrin cross-linking reagent. This catalytic assembly was active for the selective oxidation of 2-alkanols to 2-alkanones with aqueous H2O2 with reactions presumably occurring at a hydrophobic domain. Most importantly, the catalyst showed distinctive lipophiloselectivity, that is selectivity as a function of the lipophilic nature of a reaction substrate. The lipophiloselectivity was proportional to the relative partition coefficient (1-octanol/water) of the substrates.

67 citations

Journal ArticleDOI
TL;DR: In this paper, a mono-substituted Keggin-polyoxymetalate complex Na 6 [SiW 11 ZnH 2 O 40 ]·12H 2O was demonstrated to be an effective catalyst for the selective oxidation of alcohols in the presence of hydrogen peroxide as oxidant.

67 citations

Journal ArticleDOI
TL;DR: In this paper, a polyoxometalate-based 4d−4f heterometallic compound, [Ag3(H2O)2}{Ce2(H 2O)12}H5⊂{H2W11Ce(H&O)4O39}2]·8H2Os (1), has been synthesized and characterized by routine methods.
Abstract: A new polyoxometalate-based 4d−4f heterometallic compound, [{Ag3(H2O)2}{Ce2(H2O)12}H5⊂{H2W11Ce(H2O)4O39}2]·8H2O (1), has been synthesized and characterized by routine methods. In 1, the dimers constructed by two monosubstituted α-metatungstate [H2W11{Ce(H2O)4}O39]7− (simplified as {W11Ce}7−) units are linked by CeIII and AgI to form two-dimensional (2D) networks, and these networks are further connected by AgI−AgI ({Ag2}2+) bonds to obtain a purely inorganic three-dimensional (3D) framework with two kinds of channels along the [1 0 0] and [0 1 0] directions. Furthermore, 1 exhibits reversible water sorption capability.

66 citations

Journal ArticleDOI
TL;DR: A new way for devising HER electrocatalysts with low cost using POM-encapsulated MONT frameworks, which are very active for HER (H+ can diffuse easily through the pores of the MONTs).
Abstract: Two novel polyoxometalate (POM)-encapsulated metal–organic nanotube (MONT) framework crystalline materials with unprecedented copper-mixed ligands, HUST-200 and HUST-201, have been successfully synthesized by an effective synthesis strategy. The encapsulation not only provides a shield to increase the chemical stability, but also does not affect its catalytic activity, and, therefore, the crystalline materials are very active for HER (H+ can diffuse easily through the pores of the MONTs). Remarkably, HUST-200 displays a low overpotential of 131 mV (catalytic current density is equal to 10 mA·cm–2). This work thus offers a new way for devising HER electrocatalysts with low cost using POM-encapsulated MONT frameworks.

66 citations


Network Information
Related Topics (5)
Catalysis
400.9K papers, 8.7M citations
91% related
Alkyl
223.5K papers, 2M citations
87% related
Photocatalysis
67K papers, 2.1M citations
87% related
Crystal structure
100.9K papers, 1.5M citations
87% related
Cyclic voltammetry
55.9K papers, 1.4M citations
87% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023246
2022566
2021213
2020218
2019187
2018216