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1.
Chem Commun (Camb) ; 59(72): 10801-10804, 2023 Sep 07.
Article in English | MEDLINE | ID: mdl-37594189

ABSTRACT

A multi-component coordination compound, in which ruthenium antenna complexes are connected to a polyoxotungstate core is presented. This hybrid cluster effectively promotes the electrochemical conversion of CO2 to C1 feedstocks, the selectivity of which can be controlled by the acidity of the media.

2.
Angew Chem Int Ed Engl ; 62(23): e202302446, 2023 Jun 05.
Article in English | MEDLINE | ID: mdl-36988545

ABSTRACT

Herein, we report the synthesis and characterization of a new class of hybrid Wells-Dawson polyoxometalate (POM) containing a diphosphoryl group (P2 O6 X) of the general formula [P2 W17 O57 (P2 O6 X)]6- (X=O, NH, or CR1 R2 ). Modifying the bridging unit X was found to impact the redox potentials of the POM. The ease with which a range of α-functionalized diphosphonic acids (X=CR1 R2 ) can be prepared provides possibilities to access diverse functionalized hybrid POMs. Compared to existing phosphonate hybrid Wells-Dawson POMs, diphosphoryl-substituted POMs offer a wider tunable redox window and enhanced hydrolytic stability. This study provides a basis for the rational design and synthesis of next-generation hybrid Wells-Dawson POMs.

3.
Angew Chem Int Ed Engl ; 62(12): e202216066, 2023 Mar 13.
Article in English | MEDLINE | ID: mdl-36637995

ABSTRACT

The mixing of [V10 O28 ]6- decavanadate anions with a dicationic gemini surfactant (gem) leads to the spontaneous self-assembly of surfactant-templated nanostructured arrays of decavanadate clusters. Calcination of the material under air yields highly crystalline, sponge-like V2 O5 (gem-V2 O5 ). In contrast, calcination of the amorphous tetrabutylammonium decavanadate allows isolation of a more agglomerated V2 O5 consisting of very small crystallites (TBA-V2 O5 ). Electrochemical analysis of the materials' performance as lithium-ion intercalation electrodes highlights the role of morphology in cathode performance. The large crystallites and long-range microstructure of the gem-V2 O5 cathode deliver higher initial capacity and superior capacity retention than TBA-V2 O5 . The smaller crystallite size and higher surface area of TBA-V2 O5 allow faster lithium insertion and superior rate performance to gem-V2 O5 .

4.
Int J Law Psychiatry ; 82: 101780, 2022.
Article in English | MEDLINE | ID: mdl-35279456

ABSTRACT

Health care organizations are obligated to provide safe and effective treatment to their patients and also protect the safety of their workers. This paper analyzes the tensions arising from legislative regimes that, respectively, protect privacy and workplace safety, using a large, tertiary high-secure forensic psychiatric hospital in Ontario, Canada, as an example. In Ontario, the Personal Health Information Protection Act (PHIPA) prohibits personal health information (PHI) from being disclosed to individuals who fall outside the "circle of care," including nonclinical employees who have direct involvement with patients and may be at risk of violence. PHIPA permits the disclosure of information where there is a risk of violence, but the statute's scheme for privacy protection was not designed to address, and may not be compatible with, the operations and requirements of high-secure forensic and other psychiatric hospitals. At the same time, the Occupational Health and Safety Act (OHSA) creates a regulatory framework that sets health and safety standards, including an employer's duty to disclose the risk of violence. OHSA prosecutions and proceedings demonstrate how these duties have been enforced against psychiatric hospitals. We examine this regulatory backdrop, explaining that PHIPA provides little guidance to psychiatric hospitals, where the risk of violence is elevated. We also discuss issues of dual compliance that arise from a hospital's legal obligations under PHIPA and OHSA. Finally, we turn to the ongoing clinical and operational challenges, suggesting strategies for increasing staff safety. These include strengthening the therapeutic alliance and providing patients with the option of consenting to disclosure of PHI to those outside the circle of care.


Subject(s)
Hospitals, Psychiatric , Privacy , Humans , Ontario , Workplace
5.
Fundam Clin Pharmacol ; 36(3): 563-571, 2022 Jun.
Article in English | MEDLINE | ID: mdl-34904750

ABSTRACT

There are few nationwide descriptive studies of longitudinal drug use and residual cardiovascular risk in patients with myocardial infarction (MI) in contemporary clinical practice. The objectives of this work were to describe characteristics and longitudinal cardiovascular drug use of patients with a first acute MI in Norway, and to quantify residual risks of cardiovascular events and death. Using nationwide health registries in Norway, we identified 43 750 adults with a first MI (2010 to 2015) and ≥1 prescription for antiplatelet medication. We described cardiovascular medication post-MI and calculated residual cardiovascular risks. Between 3 months and 13-15 months post MI, medication use dropped from 93.3% to 75.1% for low-dose aspirin, 78.1% to 11.0% for dual antiplatelet therapy, 91.6% to 78.7% for antihypertensives, and 88.0% to 70.7% for lipid-lowering therapy. Incidence rate ratios (IRRs) for recurrent MI were similar between subpopulations at 12 months and notably different at 12-36 months. IRRs (95% CIs) at 12-36 months were 1.52 (1.26-1.82) for 65-74 years, 2.26 (1.88-2.71) for 75-84 years, and 3.97 (3.29-4.79) for ≥85 years (vs. 18-49 years), 2.42 (2.18-2.69) for those with ischaemic heart disease (IHD), 2.26 (1.97-2.59) for peripheral artery disease (PAD), 2.17 (1.98-2.36) for hypertension, and 1.82 (1.65-2.01) for diabetes. In conclusion, secondary prevention medication use 13-15 months following a first MI is suboptimal among patients in Norway. The elderly and those with IHD, PAD, diabetes, or hypertension are at high-risk for recurrent MI/stroke/death and should be managed closely beyond the first year.


Subject(s)
Cardiovascular Diseases , Diabetes Mellitus , Hypertension , Myocardial Infarction , Peripheral Arterial Disease , Adult , Aged , Cardiovascular Diseases/diagnosis , Cardiovascular Diseases/drug therapy , Cardiovascular Diseases/epidemiology , Cohort Studies , Heart Disease Risk Factors , Humans , Hypertension/complications , Myocardial Infarction/drug therapy , Myocardial Infarction/epidemiology , Peripheral Arterial Disease/complications , Peripheral Arterial Disease/epidemiology , Risk Factors
6.
Chem Soc Rev ; 51(1): 293-328, 2022 Jan 04.
Article in English | MEDLINE | ID: mdl-34889926

ABSTRACT

This review provides a comprehensive overview of recent advances in the supramolecular organisation and hierarchical self-assembly of organo-functionalised hybrid polyoxometalates (hereafter referred to as hybrid POMs), and their emerging role as multi-functional building blocks in the construction of new nanomaterials. Polyoxometalates have long been studied as a fascinating outgrowth of traditional metal-oxide chemistry, where the unusual position they occupy between individual metal oxoanions and solid-state bulk oxides imbues them with a range of attractive properties (e.g. solubility, high structural modularity and tuneable properties/reactivity). Specifically, the capacity for POMs to be covalently coupled to an effectively limitless range of organic moieties has opened exciting new avenues in their rational design, while the combination of distinct organic and inorganic components facilitates the formation of complex molecular architectures and the emergence of new, unique functionalities. Here, we present a detailed discussion of the design opportunities afforded by hybrid POMs, where fine control over their size, topology and their covalent and non-covalent interactions with a range of other species and/or substrates makes them ideal building blocks in the assembly of a broad range of supramolecular hybrid nanomaterials. We review both direct self-assembly approaches (encompassing both solution and solid-state approaches) and the non-covalent interactions of hybrid POMs with a range of suitable substrates (including cavitands, carbon nanotubes and biological systems), while giving key consideration to the underlying driving forces in each case. Ultimately, this review aims to demonstrate the enormous potential that the rational assembly of hybrid POM clusters shows for the development of next-generation nanomaterials with applications in areas as diverse as catalysis, energy-storage and molecular biology, while providing our perspective on where the next major developments in the field may emerge.


Subject(s)
Nanostructures , Nanotubes, Carbon , Anions , Polyelectrolytes
7.
Angew Chem Int Ed Engl ; 61(8): e202115619, 2022 Feb 14.
Article in English | MEDLINE | ID: mdl-34919306

ABSTRACT

We describe the preparation of hybrid redox materials based on polyoxomolybdates encapsulated within single-walled carbon nanotubes (SWNTs). Polyoxomolybdates readily oxidize SWNTs under ambient conditions in solution, and here we study their charge-transfer interactions with SWNTs to provide detailed mechanistic insights into the redox-driven encapsulation of these and similar nanoclusters. We are able to correlate the relative redox potentials of the encapsulated clusters with the level of SWNT oxidation in the resultant hybrid materials and use this to show that precise redox tuning is a necessary requirement for successful encapsulation. The host-guest redox materials described here exhibit exceptional electrochemical stability, retaining up to 86 % of their charge capacity over 1000 oxidation/reduction cycles, despite the typical lability and solution-phase electrochemical instability of the polyoxomolybdates we have explored. Our findings illustrate the broad applicability of the redox-driven encapsulation approach to the design and fabrication of tunable, highly conductive, ultra-stable nanoconfined energy materials.

8.
Chem Soc Rev ; 50(10): 5863-5883, 2021 May 24.
Article in English | MEDLINE | ID: mdl-34027958

ABSTRACT

This Tutorial Review describes how the development of dissolved redox-active molecules is beginning to unlock the potential of three of the most promising 'next-generation' battery technologies - lithium-air, lithium-sulfur and redox-flow batteries. Redox-active molecules act as mediators in lithium-air and lithium-sulfur batteries, shuttling charge between electrodes and substrate systems and improving cell performance. In contrast, they act as the charge-storing components in flow batteries. However, in each case the performance of the molecular species is strongly linked to their solubility, electrochemical and chemical stability, and redox potentials. Herein we describe key examples of the use of redox-active molecules in each of these battery technologies and discuss the challenges and opportunities presented by the development and use of redox-active molecules in these applications. We conclude by issuing a "call to arms" to our colleagues within the wider chemical community, whose synthetic, computational, and analytical skills can potentially make invaluable contributions to the development of next-generation batteries and help to unlock of world of potential energy-storage applications.

9.
Biomater Sci ; 9(16): 5397-5406, 2021 Aug 21.
Article in English | MEDLINE | ID: mdl-33988192

ABSTRACT

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.


Subject(s)
Anti-Infective Agents , Metal Nanoparticles , Anti-Infective Agents/pharmacology , Escherichia coli , Microbial Sensitivity Tests , Silver
10.
Chem Commun (Camb) ; 56(59): 8237-8240, 2020 Jul 28.
Article in English | MEDLINE | ID: mdl-32558835

ABSTRACT

An asymmetrically functionalised Wells-Dawson organic-inorganic hybrid polyoxometalate has been post-functionalised by Pt2+ coordination, and demonstrates self-assembly into surface-decorated micellar nanostructures. This multifunctional hybrid material is found to be a redox-active soft nanomaterial and demonstrates a new molecular design strategy with potential for applications in photo- or electro-catalysis.

11.
Angew Chem Int Ed Engl ; 59(34): 14331-14335, 2020 Aug 17.
Article in English | MEDLINE | ID: mdl-32432351

ABSTRACT

We report the design and preparation of multifunctional hybrid nanomaterials through the stabilization of gold nanoparticles with thiol-functionalised hybrid organic-inorganic polyoxometalates (POMs). The covalent attachment of the hybrid POM forms new nanocomposites that are stable at temperatures and pH values which destroy analogous electrostatically functionalised nanocomposites. Photoelectrochemical analysis revealed the unique photochemical and redox properties of these systems.

12.
Angew Chem Int Ed Engl ; 58(50): 18281-18285, 2019 Dec 09.
Article in English | MEDLINE | ID: mdl-31595597

ABSTRACT

Access to asymmetrically functionalized polyoxometalates is a grand challenge as it could lead to new molecular nanomaterials with multiple or modular functionality. Now, a simple one-pot synthetic approach to the isolation of an asymmetrically functionalized organic-inorganic hybrid Wells-Dawson polyoxometalate in good yield is presented. The cluster bears two organophosphonate moieties with contrasting physical properties: a chelating metal-binding group, and a long aliphatic chain that facilitates solvent-dependent self-assembly into soft nanostructures. The orthogonal properties of the modular system are effectively demonstrated by controlled assembly of POM-based redox-active nanoparticles. This simple, high-yielding synthetic method is a promising new approach to the preparation of multi-functional hybrid metal oxide clusters, supermolecular systems, and soft-nanomaterials.

13.
Angew Chem Int Ed Engl ; 58(17): 5658-5662, 2019 Apr 16.
Article in English | MEDLINE | ID: mdl-30753754

ABSTRACT

A mononuclear FeII complex, prepared with a Brønsted diacid ligand, H2 L (H2 L=2-[5-phenyl-1H-pyrazole-3-yl] 6-benzimidazole pyridine), shows switchable physical properties and was isolated in five different electronic states. The spin crossover (SCO) complex, [FeII (H2 L)2 ](BF4 )2 (1A ), exhibits abrupt spin transition at T1/2 =258 K, and treatment with base yields a deprotonated analogue [FeII (HL)2 ] (1B ), which shows gradual SCO above 350 K. A range of FeIII analogues were also characterized. [FeIII (HL)(H2 L)](BF4 )Cl (1C ) has an S=5/2 spin state, while the deprotonated complexes [FeIII (L)(HL)], (1D ), and (TEA)[FeIII (L)2 ], (1E ) exist in the low-spin S=1/2 state. The electronic properties of the five complexes were fully characterized and we demonstrate in situ switching between multiple states in both solution and the solid-state. The versatility of this simple mononuclear system illustrates how proton donor/acceptor ligands can vastly increase the range of accessible states in switchable molecular devices.

14.
Dalton Trans ; 47(31): 10590-10594, 2018 Aug 21.
Article in English | MEDLINE | ID: mdl-29770403

ABSTRACT

A new post-functionalization strategy for hybrid polyoxometalate (POM) clusters is presented, whereby the electronic properties and visible-light driven oxidative reactivity of the POM core can be altered by controlled addition of transition metal ions. The structure of three new metal-functionalised derivatives of a phosphonate hybrid-POM are discussed, alongside a comparison of their electrochemical, photo-chemical and photo-oxidative properties.

15.
Dalton Trans ; 47(15): 5120-5136, 2018 Apr 17.
Article in English | MEDLINE | ID: mdl-29517788

ABSTRACT

Finding new ways of using visible light (or, more specifically, solar irradiation) to drive commercially significant and/or challenging chemical processes is an ongoing research goal. Polyoxometalates (POMs) are discrete, metal-oxide clusters which are cheap, robust and easily synthesised but can also act as versatile molecular building blocks, allowing for astonishing variety in their structures and properties. In particular, the rich redox chemistry and inherent photo-activity of POMs makes them attractive for use in a variety of photochemical applications, however POMs characteristically only absorb strongly in the UV region. In this perspective, we discuss the various strategies which have been employed in order to sensitise POMs to visible light, with a particular focus on hybrid inorganic-organic POM species. We will discuss the two clear photo-activation mechanisms which have been developed to date and provide an outlook on some of the possible future directions of the field.

16.
Inorg Chem ; 56(20): 12169-12177, 2017 Oct 16.
Article in English | MEDLINE | ID: mdl-28820581

ABSTRACT

This study explores a new method to maximize the visible-light-driven photocatalytic performance of organic-inorganic hybrid polyoxometalates (POMs). Experimental and theoretical investigations of a family of phosphonate-substituted POMs show that modification of grafted organic moieties can be used to tune the electronic structure and photoactivity of the metal oxide component. Unlike fully inorganic polyoxotungstates, these organic-inorganic hybrid species are responsive to visible light and function as photocatalysts (λ > 420 nm) in the decomposition of a model environmental pollutant. The degree of photoactivation is shown to be dependent on the nature of the inductive effect exerted by the covalently grafted substituent groups. This study emphasizes the untapped potential that lies in an orbital engineering approach to hybrid-POM design and helps to underpin the next generation of bespoke, robust, and cost-effective molecular metal oxide photoactive materials and catalysts.

17.
Nat Commun ; 8: 14185, 2017 02 13.
Article in English | MEDLINE | ID: mdl-28194009

ABSTRACT

The design of highly flexible framework materials requires organic linkers, whereas inorganic materials are more robust but inflexible. Here, by using linkable inorganic rings made up of tungsten oxide (P8W48O184) building blocks, we synthesized an inorganic single crystal material that can undergo at least eight different crystal-to-crystal transformations, with gigantic crystal volume contraction and expansion changes ranging from -2,170 to +1,720 Å3 with no reduction in crystallinity. Not only does this material undergo the largest single crystal-to-single crystal volume transformation thus far reported (to the best of our knowledge), the system also shows conformational flexibility while maintaining robustness over several cycles in the reversible uptake and release of guest molecules switching the crystal between different metamorphic states. This material combines the robustness of inorganic materials with the flexibility of organic frameworks, thereby challenging the notion that flexible materials with robustness are mutually exclusive.

18.
PLoS Negl Trop Dis ; 11(1): e0005186, 2017 01.
Article in English | MEDLINE | ID: mdl-28125649

ABSTRACT

We have examined the remains of a Pilgrim burial from St Mary Magdalen, Winchester. The individual was a young adult male, aged around 18-25 years at the time of death. Radiocarbon dating showed the remains dated to the late 11th-early 12th centuries, a time when pilgrimages were at their height in Europe. Several lines of evidence in connection with the burial suggested this was an individual of some means and prestige. Although buried within the leprosarium cemetery, the skeleton showed only minimal skeletal evidence for leprosy, which was confined to the bones of the feet and legs. Nonetheless, molecular testing of several skeletal elements, including uninvolved bones all showed robust evidence of DNA from Mycobacterium leprae, consistent with the lepromatous or multibacillary form of the disease. We infer that in life, this individual almost certainly suffered with multiple soft tissue lesions. Genotyping of the M.leprae strain showed this belonged to the 2F lineage, today associated with cases from South-Central and Western Asia. During osteological examination it was noted that the cranium and facial features displayed atypical morphology for northern European populations. Subsequently, geochemical isotopic analyses carried out on tooth enamel indicated that this individual was indeed not local to the Winchester region, although it was not possible to be more specific about their geographic origin.


Subject(s)
Bone and Bones/anatomy & histology , DNA, Bacterial/isolation & purification , Leprosy/history , Mycobacterium leprae/genetics , Genotype , History, Medieval , Humans , Male , Osteology , United Kingdom , Young Adult
19.
Chemistry ; 23(7): 1502-1506, 2017 Jan 31.
Article in English | MEDLINE | ID: mdl-27917549

ABSTRACT

A TTF-based (TTF=tetrathiafulvalene) tridentate ligand (α-(4'-methyl-4,5-di-n-dodecylthylthiotetrathiafulvalene-5'-ylthio)- α'-[2,2,2-tris(1-pyrazolyl)ethoxy]-p-xylene) (L) with long-chain alkyl moieties was prepared in order to obtain a new multi-redox active gelator based on a mixed-metal octanuclear complex [FeIII4 NiII4 (CN)12 (tp)4 (L)4 ](BF4 )4 (1). The magnetism, electrochemistry, and gelation behavior of 1 were studied and 1,2-dichlorobenzene solutions of 1 are shown to display thermoreversible gelation behavior at room temperature. Furthermore, the gel phase of 1 was shown to undergo room-temperature gel-to-sol transformations induced by both the oxidation and reduction of the gelator complex by F4 TCNQ or [FeII (Cp*)2 ], respectively.

20.
Chemistry ; 23(1): 47-50, 2017 01 01.
Article in English | MEDLINE | ID: mdl-27801953

ABSTRACT

Tungsten-based polyoxometalates (POMs) have been employed as UV-driven photo-catalysts for a range of organic transformations. Their photoactivity is dependent on electronic transitions between frontier orbitals and thus manipulation of orbital energy levels provides a promising means of extending their utility into the visible regime. Herein, an organic-inorganic hybrid polyoxometalate, K6 [P2 W17 O57 (PO5 H5 C7 )2 ]⋅6 C4 H9 NO, was found to exhibit enhanced redox behaviour and photochemistry compared to its purely inorganic counterparts. Hybridization with electron-withdrawing moieties was shown to tune the frontier orbital energy levels and reduce the HOMO-LUMO gap, leading to direct visible-light photoactivation of the hybrid and establishing a simple, cheap and effective approach to the generation of visible-light-activated hybrid nanomaterials.

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