Visible-light-responsive hybrid photocatalysts for quantitative conversion of CO to highly concentrated formate solutions.

Photocatalysts can use visible light to convert CO into useful products. However, to date photocatalysts for CO conversion are limited by insufficient long-term stability and low CO conversion rates. Here we report hybrid photocatalysts consisting of conjugated polymers and a ruthenium(ii)-ruthenium(ii) supramolecular photocatalyst which overcome these challenges.

Observation and enhancement through alkali metal doping of p-type conductivity in the layered oxyselenides SrZnOCuSe and BaZn O CuSe.

The optoelectronic properties of two layered copper oxyselenide compounds, with nominal composition SrZnOCuSe and BaZnOCuSe, have been investigated to determine their suitability as p-type conductors. The structure, band gaps and electrical conductivity of pristine and alkali-metal-doped samples have been determined. We find that the strontium-containing compound, SrZnOCuSe, adopts the expected tetragonal structure with 4/ symmetry, and has a band gap of 2.

Harnessing biocatalysis as a green tool in antibiotic synthesis and discovery.

Biocatalysis offers a sustainable approach to drug synthesis, leveraging the high selectivity and efficiency of enzymes. This review explores the application of biocatalysis in the early-stage synthesis of antimicrobial compounds, emphasizing its advantages over traditional chemical methods. We discuss various biocatalysts, including enzymes and whole-cell systems, and their role in the selective functionalization and preparation of antimicrobials and antibacterial building blocks.

A one-step method for generating antimicrobial nanofibre meshes coaxial electrospinning.

Respiratory diseases, including influenza, infectious pneumonia, and severe acute respiratory syndrome (SARS), are a leading cause of morbidity and mortality worldwide. The recent COVID-19 pandemic claimed over 6.9 million lives globally.

A transaminase-mediated aldol reaction and applications in cascades to styryl pyridines.

Transaminase enzymes are well established biocatalysts that are used in chemical synthesis due to their beneficial sustainability profile, regio- and stereoselectivity and substrate specificity. Here, the use of a wild-type transaminase (TAm) in enzyme cascades revealed the formation of a novel hydroxystyryl pyridine product. Subsequent studies established it was a transaminase mediated reaction where it was exhibiting apparent aldolase reactivity.

Investigating the diastereoselective synthesis of a macrocycle under Curtin-Hammett control.

This work sheds new light on the stereoselective synthesis of chiral macrocycles containing twisted aromatic units, valuable π-conjugated materials for recognition, sensing, and optoelectronics. For the first time, we use the Curtin-Hammett principle to investigate a chiral macrocyclisation reaction, revealing the potential for supramolecular π-π interactions to direct the outcome of a dynamic kinetic resolution, favouring the opposite macrocyclic product to that expected under reversible, thermodynamically controlled conditions. Specifically, a dynamic, racemic perylene diimide dye (1 : 1  : ) is strapped with an enantiopure ()-1,1'-bi-2-naphthol group (-BINOL) to form two diastereomeric macrocyclic products, the homochiral macrocycle () and the heterochiral species ().

Natural transaminase fusions for biocatalysis.

Biocatalytic approaches are used widely for the synthesis of amines from abundant or low cost starting materials. This is a fast-developing field where novel enzymes and enzyme combinations emerge quickly to enable the production of new and complex compounds. Natural multifunctional enzymes represent a part of multi-step biosynthetic pathways that ensure a one-way flux of reactants.

Torsional flexibility in zinc-benzenedicarboxylate metal-organic frameworks.

We explore the role and nature of torsional flexibility of carboxylate-benzene links in the structural chemistry of metal-organic frameworks (MOFs) based on Zn and benzenedicarboxlyate (bdc) linkers. A particular motivation is to understand the extent to which such flexibility is important in stabilising the unusual topologically aperiodic phase known as TRUMOF-1. We compare the torsion angle distributions of TRUMOF-1 models with those for crystalline Zn/1,3-bdc MOFs, including a number of new materials whose structures we report here.

Correction: Investigation of factors affecting the stability of compounds formed by isovalent substitution in layered oxychalcogenides, leading to identification of BaScOCuSe, BaYOCuSe, BaScOAgSe and BaInOAgSe.

[This corrects the article DOI: 10.1039/D1TC05051F.].

Sequence-independent, site-specific incorporation of chemical modifications to generate light-activated plasmids.

Plasmids are ubiquitous in biology, where they are used to study gene-function relationships and intricate molecular networks, and hold potential as therapeutic devices. Developing methods to control their function will advance their application in research and may also expedite their translation to clinical settings. Light is an attractive stimulus to conditionally regulate plasmid expression as it is non-invasive, and its properties such as wavelength, intensity, and duration can be adjusted to minimise cellular toxicity and increase penetration.

Magnetically driven preparation of 1-D nano-necklaces capable of MRI relaxation enhancement.

We report a novel magnetically-facilitated approach to produce 1-D 'nano-necklace' arrays composed of 0-D magnetic nanoparticles, which are assembled and coated with an oxide layer to produce semi-flexible core@shell type structures. These 'nano-necklaces' demonstrate good MRI relaxation properties despite their coating and permanent alignment, with low field enhancement due to structural and magnetocrystalline anisotropy.

Highly selective CO photoreduction to CO on MOF-derived TiO.

Metal-Organic Framework (MOF)-derived TiO, synthesised through the calcination of MIL-125-NH, is investigated for its potential as a CO photoreduction catalyst. The effect of the reaction parameters: irradiance, temperature and partial pressure of water was investigated. Using a two-level design of experiments, we were able to evaluate the influence of each parameter and their potential interactions on the reaction products, specifically the production of CO and CH.

The Discovery of Imine Reductases and their Utilisation for the Synthesis of Tetrahydroisoquinolines.

Imine reductases (IREDs) are NADPH-dependent enzymes with significant biocatalytic potential for the synthesis of primary, secondary, and tertiary chiral amines. Their applications include the reduction of cyclic imines and the reductive amination of prochiral ketones. In this study, twenty-nine novel IREDs were revealed through genome mining.

Enabling the formation of native mAb, Fab' and Fc-conjugates using a bis-disulfide bridging reagent to achieve tunable payload-to-antibody ratios (PARs).

Either as full IgGs or as fragments (Fabs, Fc, ), antibodies have received tremendous attention in the development of new therapeutics such as antibody-drug conjugates (ADCs). The production of ADCs involves the grafting of active payloads onto an antibody, which is generally enabled by the site-selective modification of native or engineered antibodies chemical or enzymatic methods. Whatever method is employed, controlling the payload-antibody ratio (PAR) is a challenge in terms of multiple aspects including: (i) obtaining homogeneous protein conjugates; (ii) obtaining unusual PARs (PAR is rarely other than 2, 4 or 8); (iii) using a single method to access a range of different PARs; (iv) applicability to various antibody formats; and (v) flexibility for the production of heterofunctional antibody-conjugates ( attachment of multiple types of payloads).

Mechanoenzymatic reactions for the hydrolysis of PET.

Recent advances in the enzymatic degradation of poly(ethylene terphthalate) (PET) have led to a number of PET hydrolytic enzymes and mutants being developed. With the amount of PET building up in the natural world, there is a pressing need to develop scalable methods of breaking down the polymer into its monomers for recycling or other uses. Mechanoenzymatic reactions have gained traction recently as a green and efficient alternative to traditional biocatalytic reactions.

Wavelength dependent mechanism of phenolate photooxidation in aqueous solution.

Phenolate photooxidation is integral to a range of biological processes, yet the mechanism of electron ejection has been disputed. Here, we combine femtosecond transient absorption spectroscopy, liquid-microjet photoelectron spectroscopy and high-level quantum chemistry calculations to investigate the photooxidation dynamics of aqueous phenolate following excitation at a range of wavelengths, from the onset of the S-S absorption band to the peak of the S-S band. We find that for ≥ 266 nm, electron ejection occurs from the S state into the continuum associated with the contact pair in which the PhO˙ radical is in its ground electronic state.

The use of tyrosinases in a chemoenzymatic cascade as a peptide ligation strategy.

Peptides play many key roles in biological systems and numerous methods have been developed to generate both natural and unnatural peptides. However, straightforward, reliable coupling methods that can be achieved under mild reactions conditions are still sought after. In this work, a new N-terminal tyrosine-containing peptide ligation method with aldehydes, utilising a Pictet-Spengler reaction is described.

Facile and selective -alkylation of gentamicin antibiotics chemoenzymatic synthesis.

The rise and spread of antimicrobial resistance has necessitated the development of novel antimicrobials which are effective against drug resistant pathogens. Aminoglycoside antibiotics (AGAs) remain one of our most effective classes of bactericidal drugs. However, they are challenging molecules to selectively modify by chemical synthesis, requiring the use of extensive protection and deprotection steps leading to long, atom- and step-inefficient synthetic routes.

Transparent and conducting boron doped ZnO thin films grown by aerosol assisted chemical vapor deposition.

ZnO based transparent conducting oxides are important as they provide an alternative to the more expensive Sn : InO that currently dominates the industry. Here, we investigate B-doped ZnO thin films grown aerosol assisted chemical vapour deposition. B : ZnO films were produced from zinc acetate and triethylborane using either tetrahydrofuran or methanol (MeOH) as the solvent.

Hybrid nanostructures for electrochemical potassium storage.

The wide availability and low cost of potassium resources have made electrochemical potassium storage a promising energy storage solution for sustainable decarbonisation. Research activities have been rapidly increasing in the last few years to investigate various potassium batteries such as K-ion batteries (KIBs), K-S batteries and K-Se batteries. The electrode materials of these battery technologies are being extensively studied to examine their suitability and performance, and the utilisation of hybrid nanostructures has undoubtedly contributed to the advancement of the performance.

Functionalisation of ethereal-based saturated heterocycles with concomitant aerobic C-H activation and C-C bond formation.

With an ever-growing emphasis on sustainable synthesis, aerobic C-H activation (the use of oxygen in air to activate C-H bonds) represents a highly attractive conduit for the development of novel synthetic methodologies. Herein, we report the air mediated functionalisation of various saturated heterocycles and ethers aerobically generated radical intermediates to form new C-C bonds using acetylenic and vinyl triflones as radical acceptors. This enables access to a variety of acetylenic and vinyl substituted saturated heterocycles that are rich in synthetic value.

Direct Conversion of Hydrazones to Amines using Transaminases.

Transaminase enzymes (TAms) have been widely used for the amination of aldehydes and ketones, often resulting in optically pure products. In this work, transaminases were directly reacted with hydrazones in a novel approach to form amine products. Several substrates were investigated, including those with furan and phenyl moieties.