We report the formation of two polyoxotungstates of the general formula M6(PW6O26)(α-P2W15O56)2(H2O)2(23-) (M = Co(II) or Mn(II)), which contain {PW6} fragments generated from the P2W15O56(12-) ...precursor, which demonstrates for the first time the transformation of a Dawson lacunae into a Keggin lacunary building block. Solution analysis of the clusters has been conducted via electrospray ionisation mass spectrometry.
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 PW11O39(SiPh)2O3– and PW11O39{P(O)Ph}23–. The functionalized POM‐ILs were found to be more thermally stable than their molecular precursors and comparison of their electrochemical properties showed that the tunable electronic structures of the POM anions determined the redox chemistry of the hybrid materials.
Two hybrid polyoxometalate ionic liquids (POM‐ILs) were formed by pairing bulky phosphonium cations with organosiloxane and organophosphonate‐functionalized Keggin‐type polyoxometalates. The hybrid POM‐ILs were found to exhibit rich electrochemistry determined by the nature of the POM modification, and to be more thermally stable than their molecular precursors.
The synthesis of a series of discrete lanthanide-capped polyoxovanadate cages is presented along with magnetic and electrochemical measurements which reveal a redox active dodecavanadate cluster with ...potential as a new functional building unit in polyoxovanadate chemistry.
The use of electrically charged, polymerized ionic liquids (polyILs) offers opportunities for the development of gel–polymer electrolytes (GPEs), but the rational design of such systems is in its ...infancy. In this work, we compare the properties of polyIL/IL GPEs based on 1-butyl-3-(4-vinylbenzyl)imidazolium bis(trifluromethanesulfonyl)imide containing trapped ammonium-based protic ionic liquids (ILs) with an analogous series based on the electrically neutral host polymer 1-(4-vinylbenzyl)imidazole. The materials are synthesized by photopolymerizing ionic and neutral monomers in the presence of diethylmethylammonium trifluoromethanesulfonate, demaTfO, diethylmethylammonium trifluoroacetate, demaTFAc, and diethylmethylammonium bistrifluoromethanesulfonylimide, demaTf2N, respectively. The resulting materials are characterized using electron microscopy, infrared spectroscopy, thermal analysis, Raman spectroscopy, and AC-impedance analysis. Spectroscopic analysis confirms that the ILs are distributed throughout the polymers, unless the GPE also contains poly(diallyldimethylammonium) bistrifluoromethanesulfonylimide, when separation of the components occurs. The polyIL/IL GPEs are more electrochemically and thermally stable, and up to six times more conductive, than the materials based on the neutral host. As a proof-of-concept demonstration, we show that polyIL/IL gels can be 3D printed using readily available 3D-printing hardware.
Abstract
Aims
To evaluate whether left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS), automatically calculated by artificial intelligence (AI), increases the diagnostic ...performance of stress echocardiography (SE) for coronary artery disease (CAD) detection.
Methods and results
SEs from 512 participants who underwent a clinically indicated SE (with or without contrast) for the evaluation of CAD from seven hospitals in the UK and US were studied. Visual wall motion scoring (WMS) was performed to identify inducible ischaemia. In addition, SE images at rest and stress underwent AI contouring for automated calculation of AI-LVEF and AI-GLS (apical two and four chamber images only) with Ultromics EchoGo Core 1.0. Receiver operator characteristic curves and multivariable risk models were used to assess accuracy for identification of participants subsequently found to have CAD on angiography. Participants with significant CAD were more likely to have abnormal WMS, AI-LVEF, and AI-GLS values at rest and stress (all P < 0.001). The areas under the receiver operating characteristics for WMS index, AI-LVEF, and AI-GLS at peak stress were 0.92, 0.86, and 0.82, respectively, with cut-offs of 1.12, 64%, and −17.2%, respectively. Multivariable analysis demonstrated that addition of peak AI-LVEF or peak AI-GLS to WMS significantly improved model discrimination of CAD C-statistic (bootstrapping 2.5th, 97.5th percentile) from 0.78 (0.69–0.87) to 0.83 (0.74–0.91) or 0.84 (0.75–0.92), respectively.
Conclusion
AI calculation of LVEF and GLS by contouring of contrast-enhanced and unenhanced SEs at rest and stress is feasible and independently improves the identification of obstructive CAD beyond conventional WMSI.
The self-assembly of hierarchical nanostructures on surfaces is a promising strategy for the development of a wide range of new technologies, such as energy-storage devices and sensors. In this work ...we show that amphiphilic, organofunctionalized hybrid polyoxometalates spontaneously self-assemble on glassy carbon, graphene oxide, and highly oriented pyrolytic graphite to create hierarchical redox-active nanostructures. The electrochemical behaviour and stability of these supramolecular, nanostructured assemblies is explored in detail and their morphology is determined by comprehensive optical and spectroscopic analyses. The spontaneous assembly of these hybrid nanomaterials on both hydrophilic and hydrophobic carbons is compared and we discuss how this strategy may be a new, simple, and effective method of fabricating hierarchically modified electrode surfaces.
The spontaneous self-assembly of hierarchical polyoxometalate-based nanostructures on a range of carbon surfaces is demonstrated
via
the use of amphiphilic hybrid-polyoxometalate building blocks.
Double-chain redox-active surfactants based on hybrid polyoxometalates show solvent-dependent assembly into nanoscale micellar architectures. These organic-inorganic hybrid amphiphiles, of the ...general formula K
6
P
2
W
17
O
61
(POC
6
H
4
O(C
n
H
2
n
+1
))
2
, were prepared with varying aliphatic chain lengths (
n
= 10, 12, 14, 16, 18 and 20) and display different multi-electron redox behaviours in their molecular and supramolecular forms. Furthermore, modification of the length of the hydrophobic tail is an effective strategy for controlling the stability and electronic properties of the supramolecular nanostructures.
Double-chain redox-active surfactants based on hybrid polyoxometalates show solvent-dependent assembly into nanoscale micellar architectures.
3D printable materials based on polymeric ionic liquids (PILs) capable of controlling the synthesis and stabilisation of silver nanoparticles (AgNPs) and their synergistic antimicrobial activity are ...reported. The interaction of the ionic liquid moieties with the silver precursor enabled the controlled
in situ
formation and stabilisation of AgNPs
via
extended UV photoreduction after the printing process, thus demonstrating an effective decoupling of the device manufacturing from the on-demand generation of nanomaterials, which avoids the potential aging of the nanomaterials through oxidation. The printed devices showed a multi-functional and tuneable microbicidal activity against Gram positive (
B. subtilis
) and Gram negative (
E. coli
) bacteria and against the mould
Aspergillus niger
. While the polymeric material alone was found to be bacteriostatic, the AgNPs conferred bactericidal properties to the material. Combining PIL-based materials with functionalities, such as
in situ
and photoactivated on-demand fabricated antimicrobial AgNPs, provides a synergistic functionality that could be harnessed for a variety of applications, especially when coupled to the freedom of design inherent to additive manufacturing techniques.
Decoupling the photopolymerisation of polymerisable ionic liquids (PILs) from the photoreduction of AgSbF
6
to form Ag nanoparticle-loaded antimicrobial devices. Antimicrobial and fungicidal properties have been demonstrated.
The heteropolyvanadate cluster (n-C(4)H(9))(4)N(4)Mn(IV)V(12)O(34)·2CH(3)CN has been isolated by cation exchange from K(10)(Mn(IV)V(11)O(32))(2)·20H(2)O. The structural transformation has been ...confirmed by X-ray single crystal structure determination and cryospray ionization mass spectrometry measurements.
Simple organic functionalization was shown to be a cost‐effective and durable approach to the visible‐light photoactivation of polyoxometalates (POMs). A new organic–inorganic hybrid polyoxometalate ...showed greatly enhanced photocatalytic activity in the visible region compared with analogous, non‐hybridized POM clusters. The new hybrid POM takes center stage in the cover art, illuminated by the sun of (possibly) a new dawn in molecular metal oxide photochemistry. More information can be found in the Communication by G. N. Newton and H. H. Oshio et al. on page 47 ff.
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