Physical and Electrochemical Modulation of Polyoxometalate Ionic Liquids via Organic Functionalization

Abstract

The synthesis and characterization of two new organic/inorganic hybrid polyoxometalate ionic liquids (POM-ILs) is described. The POM-ILs were formed by pairing bulky trihexyl(tetradecyl)phosphonium cations [THTP] + with organosiloxane and organophosphonate-functionalized Keggin-type POMs [PW 11 O 39 (SiPh) 2 O] 3and [PW 11 O 39 {P(O)Ph} 2 ] 3-. The func-[a] GSK 456 Scheme 1. Synthetic scheme for the synthesis of compound 2. Blue spheres/polyhedra=W; magenta=P; red=O; grey=C; white=H. Cations are included only as text for clarity.

Organic–Inorganic Hybrid Polyoxotungstates As Configurable Charge Carriers for High Energy Redox Flow Batteries

“…The redox couples accessed during the voltammetric experiment are as follows: The midpoint potential, E mid , peak-to-peak separation, Δ E p , and ratio of anodic to cathodic peak currents, i p,a / i p,c , of each redox couple are provided in Table . These data are in good agreement with the values found in the literature …”

“…The synthesis of TBA 3 W 11 SiPh was carried out using literature precedent. 30 Trichlorophenylsilane (0.44 cm 3 , 2.7 mmol) was added to a solution of (TBA) 4 H 3 [PW 11 O 39 ] (5.0 g, 1.4 mmol) in acetonitrile (60 cm 3 ), stirred at room temperature for 15 h, and then evaporated to dryness. The crude product was dissolved in the minimum possible volume of acetonitrile and precipitated by the addition of water.…”

“…The covalent linker plays an important role in governing the electronic properties of hybrid POMs, and allows for tuning of the charge carrier redox potentials. Organic–inorganic hybrid POMs have already been used in catalysis, energy materials, and life sciences and can be further functionalized to yield novel soft redox materials. − Hybridization can be applied to a broad range of POMs, which presents the opportunity to develop multielectron charge carriers across a wide potential range. Successful implementation of this technique could lead to high energy density asymmetric POM/POM nonaqueous RFBs.…”

Modelling local structural and electronic consequences of proton and hydrogen-atom uptake in VO2 with polyoxovanadate clusters

“…However, most studies have been rooted in the development of methodologies for the organofunctionalization of polyoxotungstates, focused on formation of bridging siloxide ligands at the nucleophilic terminal oxide ligands of Lacunary assemblies. [42][43][44][45][46][47][48][49][50] By contrast, the formation of terminal siloxide moieties at the surface of plenary POMs, as observed following addition of TMSOTf to 1-V IV 6O7 2-, is quite rare. The single example is reported in the case of a niobiumfunctionalised polyoxotungstate ion, [Nb2W4O19] 4-.…”

A Cooperative Photoactive Class-I Hybrid Polyoxometalate With Benzothiadiazole–Imidazolium Cations

“…Class I hybrids remain the most prolifically reported and studied due to their ease of synthesis through simple metathesis reactions and their compatibility with any anionic POM structure. Generally, the physical properties of the POMs are dominated and controlled by the cation, and thus, Class I hybridization is a highly attractive route toward POM-based functional materials such as POM ionic liquids (POM-ILs) (Kibler et al, 2019 ), POM charge transfer salts (Xu et al, 2010 ), and POM-decorated polymers (Herrmann et al, 2015 ).…”