Organofunctionalized borotungstate polyoxometalates as tunable photocatalysts for oxidative dimerization of amines.

Organofunctionalized borotungstate Keggin polyoxometalates, ( BuN)H[HBWO(P(O)Ph)] (PBW), ( BuN)H[HBWO(As(O)Ph)] (AsBW), and ( BuN)[HBWO(PhSiOSiPh)] (SiBW), were synthesized and structurally characterized. Cyclic voltammetry showed that the electronic properties of the clusters are dependent on the nature of the appended main group atoms (P, As, or Si). The first reduction potentials were found to shift positively with respect to that of the unmodified parent species ( BuN)[BWO], with PBW showing the largest shift at +100 mV.

A lithium-air battery and gas handling system demonstrator.

The lithium-air (Li-air) battery offers one of the highest practical specific energy densities of any battery system at >400 W h kg. The practical cell is expected to operate in air, which is flowed into the positive porous electrode where it forms LiO on discharge and is released as O on charge. The presence of CO and HO in the gas stream leads to the formation of oxidatively robust side products, LiCO and LiOH, respectively.

Four Redox Isomers of a [3 × 3] Copper-Iron Heterometal Grid.

A mixed-valence heterometallic nonanuclear [3 × 3] grid complex, [CuCuFe(L)](BF)·MeOH·9HO (; MeOH = methanol), was synthesized by a one-pot reaction of copper and iron ions with multidentate ligand 2,6-bis[5-(2-pyridinyl)-1-pyrazol-3-yl]pyridine (HL). showed five quasi-reversible one-electron redox processes centered at +0.74, +0.

Selective electrochemical CO conversion with a hybrid polyoxometalate.

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 CO to C1 feedstocks, the selectivity of which can be controlled by the acidity of the media.

Silver(I)-Catalyzed Synthesis of Cuneanes from Cubanes and their Investigation as Isosteres.

Bridged or caged polycyclic hydrocarbons have rigid structures that project substituents into precise regions of 3D space, making them attractive as linking groups in materials science and as building blocks for medicinal chemistry. The efficient synthesis of new or underexplored classes of such compounds is, therefore, an important objective. Herein, we describe the silver(I)-catalyzed rearrangement of 1,4-disubstituted cubanes to cuneanes, which are strained hydrocarbons that have not received much attention since they were first described in 1970.

Application of a Synthetic Ferredoxin-Inspired [4Fe4S]-Peptide Maquette as the Redox Partner for an [FeFe]-Hydrogenase.

'Bacterial-type' ferredoxins host a cubane [4Fe4S] cluster that enables these proteins to mediate electron transfer and facilitate a broad range of biological processes. Peptide maquettes based on the conserved cluster-forming motif have previously been reported and used to model the ferredoxins. Herein we explore the integration of a [4Fe4S]-peptide maquette into a H -powered electron transport chain.

Diphosphoryl-functionalized Polyoxometalates: Structurally and Electronically Tunable Hybrid Molecular Materials.

Herein, we report the synthesis and characterization of a new class of hybrid Wells-Dawson polyoxometalate (POM) containing a diphosphoryl group (P O X) of the general formula [P W O (P O X)] (X=O, NH, or CR R ). 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=CR R ) can be prepared provides possibilities to access diverse functionalized hybrid POMs.

Voltammetric Evidence of Proton Transport through the Sidewalls of Single-Walled Carbon Nanotubes.

Understanding ion transport in solid materials is crucial in the design of electrochemical devices. Of particular interest in recent years is the study of ion transport across 2-dimensional, atomically thin crystals. In this contribution, we describe the use of a host-guest hybrid redox material based on polyoxometalates (POMs) encapsulated within the internal cavities of single-walled carbon nanotubes (SWNTs) as a model system for exploring ion transport across atomically thin structures.

Electronic Structure and Photoactivity of Organoarsenic Hybrid Polyoxometalates.

Organofunctionalization of polyoxometalates (POMs) allows the preparation of hybrid molecular systems with tunable electronic properties. Currently, there are only a handful of approaches that allow for the fine-tuning of POM frontier molecular orbitals in a predictable manner. Herein, we demonstrate a new functionalization method for the Wells-Dawson polyoxotungstate [PWO] using arylarsonic acids which enables modulation of the redox and photochemical properties.

Self-Assembled Surfactant-Polyoxovanadate Soft Materials as Tuneable Vanadium Oxide Cathode Precursors for Lithium-Ion Batteries.

The mixing of [V O ] 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 V O (gem-V O ). In contrast, calcination of the amorphous tetrabutylammonium decavanadate allows isolation of a more agglomerated V O consisting of very small crystallites (TBA-V O ).

Enflurane Additive for Sodium Negative Electrodes.

Development of sodium anodes, both hard carbon (HC) and metallic, is dependent on the discovery of electrolyte formations and additives able to stabilize the interphase and support Na transport. Halogen salt additives are known to lower the energy barrier for the Na-ion charge transfer at the interface and facilitate stable Na plating/stripping in a symmetric cell configuration. Here, a halogen-rich additive for the sodium-ion battery electrolyte, 2-chloro-1,1,2-trifluoroethyl difluoromethyl ether (enflurane), is reported.

Insight into the Structural Variation and Sodium Storage Behavior of Polyoxometalates Encapsulated within Single-Walled Carbon Nanotubes.

The host-guest interaction can remarkably alter the physiochemical properties of composite materials. It is crucial to clarify the mechanism by revealing the influence of the host on the electronic structure of the guest molecules. Herein, we study the structural variation of polyoxometalates (POMs) after being confined in single-walled carbon nanotubes (SWNT).

Synthesis of New Morphinan Opioids by TBADT-Catalyzed Photochemical Functionalization at the Carbon Skeleton.

The synthesis of new morphinan opioids by the addition of photochemically generated carbon-centered radicals to substrates containing an enone in the morphinan C-ring, is described. Using tetrabutylammonium decatungstate (TBADT) as a hydrogen atom transfer photocatalyst, diverse radical donors can be used to prepare a variety of C8-functionalized morphinan opioids. This work demonstrates the late-stage modification of complex, highly functionalized substrates.

Stabilization of Polyoxometalate Charge Carriers via Redox-Driven Nanoconfinement in Single-Walled Carbon Nanotubes.

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.

Supramolecular assemblies of organo-functionalised hybrid polyoxometalates: from functional building blocks to hierarchical nanomaterials.

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 ( 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.

A ring of grids: a giant spin-crossover cluster.

Mononuclear and icosanuclear spin-crossover complexes, [Fe(HL)](BF) (1) and [FeII20(L)](BF) (2), were synthesized using an asymmetric multidentate ligand (HL). 1 has a bis-chelate structure with two protonated ligands, while 2 has a ring-shape structure comprising four [2 × 2] grid moieties and four mononuclear units.

Electrochemistry of redox-active molecules confined within narrow carbon nanotubes.

Confinement of molecules within nanocontainers can be a powerful tool for controlling the states of guest-molecules, tuning properties of host-nanocontainers and triggering the emergence of synergistic properties within the host-guest systems. Among nanocontainers, single-walled carbon nanotubes - atomically thin cylinders of carbon, with typical diameters below 2 nm and lengths reaching macroscopic dimensions - are ideal hosts for a variety of materials, including inorganic crystals, and organic, inorganic and organometallic molecules. The extremely high aspect ratio of carbon nanotubes is complemented by their functional properties, such as exceptionally high electrical conductivity and thermal, chemical and electrochemical stability, making carbon nanotubes ideal connectors between guest-molecules and macroscopic electrodes.

Prevalence, Nature, Severity and Preventability of Adverse Drug Events in Mental Health Settings: Findings from the MedicAtion relateD harm in mEntal health hospitals (MADE) Study.

Introduction: Adverse drug events (ADEs) constitute a significant problem in hospitals worldwide. However, little is known about their burden in mental health hospitals.

Objective: The objective of this study was to determine the prevalence, nature, severity and preventability of ADEs across three mental health trusts in England.

Single-molecule imaging and kinetic analysis of intermolecular polyoxometalate reactions.

We induce and study reactions of polyoxometalate (POM) molecules, [PWO] (Keggin) and [PWO] (Wells-Dawson), at the single-molecule level. Several identical carbon nanotubes aligned side by side within a bundle provided a platform for spatiotemporally resolved imaging of 100 molecules encapsulated within the nanotubes by transmission electron microscopy (TEM). Due to the entrapment of POM molecules their proximity to one another is effectively controlled, limiting molecular motion in two dimensions but leaving the third dimension available for intermolecular reactions between pairs of neighbouring molecules.

Molecular redox species for next-generation batteries.

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.

Decoupling manufacturing from application in additive manufactured antimicrobial materials.

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.

Thoracic Endotracheal Tube Insertion During Prehospital Thoracostomy: A Case Report.

This case highlights the novel use of endotracheal tubes to maintain patency of simple thoracostomies (STs) performed to relieve a tension pneumothorax after failed needle thoracostomy (NT). Treatment of a tension pneumothorax in the prehospital setting is typically performed using NT because of the minimal equipment required and rapid application. However, the variable efficacy of NT has led to a rise in the use of ST as an alternative procedure to treat a tension pneumothorax.

Clinical Characteristics of Patients Undergoing Needle Thoracostomy in a Canadian Helicopter Emergency Medical Service.

Needle thoracostomy (NT) can be a life-saving procedure when used to treat tension pneumothorax. However, there is some question regarding the efficacy of NT in the prehospital setting. Failure to treat tension pneumothorax in a helicopter emergency medical service (HEMS) setting may prove especially deleterious to the patient due to gas expansion with increasing altitude.

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

An organic-inorganic hybrid species based on the Wells-Dawson polyoxotungstate [PWO] and novel fluorescent benzothiadiazole-imidazolium cations, [BTD-4,7-ImH], has been synthesized. X-ray crystallographic analysis shows that the inorganic and organic components form a hydrogen-bonded superstructure and that the cations are revealed to be non-equivalent with varying degrees of rotation between the BTD and imidazolium rings due to competition between weak intra- and intermolecular interactions. The UV-vis diffuse reflectance spectra indicate that the hybrid has a band gap of 3.