Metal–Organic Cages with {SiW₉Ni₄} Polyoxotungstate Nodes

Abstract

A tritopic, Ni‐substituted Keggin cluster, {SiW9Ni4}, assembles with rigid dicarboxylate linkers to give rise to a set of discrete, POM2nL3n‐type structures (POM={SiW9Ni4}) with defined interior voids. The outcome of coordination‐driven self‐assemblies of these polyhedral cages—from fused dimers to trigonal prisms—was found to be sensitive to bend angles of the ditopic ligands, which vary from 122° to 180°. These polyoxotungstate‐based metal–organic polyhedra, when coupled with [Ru(bpy)3]Cl2 as a photosensitizer and triethanolamine as the electron donor, serve as highly effective catalysts for CO2 reduction, with turnover numbers up to 328 and CO selectivity as high as 96.2 %. The inner cavities of such cage structures, if functionalized or of sufficient size to encapsulate targeted guest molecules, could present a new strategy towards functional materials for potential applications.

Clustering Six Electrons within “Dawson‐Like” Polyoxometalate: An Open Route toward Its Post‐functionalization

“…The presence of an electron-rich triad in the "Dawsonlike" POM may offer a means of post-functionalizing for the first time this class of POMs whose their lacunary entities, the usual precursors for the design of new POM-based architectures, [25][26][27][28] remain elusive. Inspired by the pioneering work of Pope et al, [29] we have successfully used H 2 AsW 18 -VI' as an inorganic precursor to form the largest POM containing W IV centers reported to date.…”

Organophosphonic acid and cerium functionalized antimonotungstate with electrochemical promise in biosensing bacterial dissimilatory sulfite reductase gene sequence

“…[9][10][11] Thereby, organically functionalized POMs have been extensively developed, and an increasing plethora of POMs are reported annually. [12][13][14][15] It is believed that organic ligands (especially for those ligands with carboxylic acid groups) are exceedingly preferred, because they can not only effectively regulate the pH value of the reaction system to further inhibit the hydrolysis of Ln cations, but also connect neighbouring POM SBUs and metal centers to build neoteric structures and strengthen structural stability. [14][15][16] With the speedy development of phosphotungstates and arsenotungstates, antimonotungstates (ATs) have gradually attracted increasing interest, because antimony is in the same main group as phosphorus and arsenic.…”

“…In addition, although organic ligands can be another useful tool to join POM SBUs to build organic-inorganic hybrid POM nanoclusters or even POM-based open frameworks, [13][14][15]30 organically functionalized ATs have not been widely studied. [31][32][33] Recently, organic ligand and Ln functionalized ATs (OLLFATs) have provoked remarkable interest due to their unique structural aesthetics and novel functional features.…”

Developing Insoluble Polyoxometalate Clusters to Bridge Homogeneous and Heterogeneous Water Oxidation Photocatalysis

“…Having these attractive attributes, POMs have received considerable attention in academic research and also been successfully applied in industrial catalysis [15–17] . In particular, as an alternative to metal oxides, a substantial number of POMs have been produced for H 2 evolution, O 2 evolution, CO 2 reduction reactions and more with the aim to reduce and resolve the global challenges of the energy crisis and climate change [18–41] . POMs are usually used as homogeneous catalysts due to their good solubility in water.…”