An Isolable Base-Stabilized Diazosilenyl Cation.

In contrast to the emerging chemistry of stable diazoalkenes, there are not yet any studies devoted to heavier silicon analogues, diazosilenes. Here, we report the synthesis of a base-stabilized diazosilenyl cation 2 by the reaction of base-stabilized C-phosphonio-silyne 1 with NO. This silicon analog of diazoalkenes 2 exhibits a remarkable stability thanks to the coordination of phosphine and phosphine oxide ligands at the cationic silicon center.

Understanding ketone hydrogenation catalysis with anionic iridium(iii) complexes: the crucial role of counterion and solvation.

Catalytic asymmetric hydrogenation of ketones is an important approach to prepare valuable chiral alcohols. Understanding how transition metals promote these reactions is key to the rational design of more active, selective and sustainable catalysts. A highly unusual mechanism for asymmetric hydrogenation of acetophenone catalysed by an anionic Ir hydride system, including a strong counterion dependence on catalyst activity, is explored and rationalised here.

Investigation of the titanium-mediated catalytic enantioselective oxidation of aryl benzyl sulfides containing heterocyclic groups.

Our enantioselective oxidation protocol, based upon hydroperoxides in the presence of a titanium/(,)-hydrobenzoin catalyst, was tested for the first time with aryl benzyl sulfides containing heterocyclic moieties (2-thienyl, 2-pyridyl and benzimidazolyl), two of them being connected with the blockbuster omeprazole drug. Good yields of enantiopure sulfoxides were obtained in most cases. Two exceptions of unsatisfactory enantioselectivity in the oxidation of benzimidazolyl sulfides are reported.

Harnessing prion-inspired amyloid self-assembly for sustainable and biocompatible proton conductivity.

Protein-based materials have emerged as promising candidates for proton-conducting biomaterials. Therefore, drawing inspiration from the amino acid composition of prion-like domains, we designed short self-assembling peptides incorporating the (X-Tyr) motif, with X representing Asn, Gly and Ser, which form fibrillar structures capable of conducting protons. In this study, we conducted an analysis of the conductivity capacity of these fibers, with a focus on temperature and frequency dependence of conductivity.

Metadynamics simulations reveal alloying-dealloying processes for bimetallic PdGa nanoparticles under CO hydrogenation.

Supported bimetallic nanoparticles (NPs) often display improved catalytic performances (activity and/or selectivity). Yet, structure-activity relationships are difficult to derive due to the multitude of possible compositions, interfaces and alloys. This is notably true for bimetallic NPs used in the selective hydrogenation of CO to methanol, where the NPs respond dynamically to the chemical potential of the reactants and products.

Single electron reduction of NHC-CO-borane compounds.

The carbon dioxide radical anion [CO˙] is a highly reactive species of fundamental and synthetic interest. However, the direct one-electron reduction of CO to generate [CO˙] occurs at very negative reduction potentials, which is often a limiting factor for applications. Here, we show that NHC-CO-BR species - generated from the Frustrated Lewis Pair (FLP)-type activation of CO by N-heterocyclic carbenes (NHCs) and boranes (BR) - undergo single electron reduction at a less negative potential than free CO.

Net-clipping as a top-down approach for the prediction of topologies of MOFs built from reduced-symmetry linkers.

Reticular materials constructed from regular molecular building blocks (MBBs) have been widely explored in the past three decades. Recently, there has been increasing interest in the assembly of novel, intricate materials using less-symmetric ligands; however, current methods for predicting structure are not amenable to this increased complexity. To address this gap, we propose herein a generalised version of the net-clipping approach for anticipating the topology of metal-organic frameworks (MOFs) assembled from organic linkers and different polygonal and polyhedral MBBs.

Survival of skyrmions along granular racetracks at room temperature.

Skyrmions can be envisioned as bits of information that can be transported along nanoracetracks. However, temperature, defects, and/or granularity can produce diffusion, pinning, and, in general, modification in their dynamics. These effects may cause undesired errors in information transport.

Highly dispersed Rh single atoms over graphitic carbon nitride as a robust catalyst for the hydroformylation reaction.

Rhodium-catalysed hydroformylation, effective tool in bulk and fine-chemical synthesis, predominantly uses soluble metal complexes. For that reason, the metal leaching and the catalyst recycling are still the major drawbacks of this process. Single-atom catalysts have emerged as a powerful tool to combine the advantages of both homogeneous and heterogeneous catalysts.

Ga and Zn increase the oxygen affinity of Cu-based catalysts for the CO hydrogenation according to atomistic thermodynamics.

The direct hydrogenation of CO or CO to methanol, a highly vivid research area in the context of sustainable development, is typically carried out with Cu-based catalysts. Specific elements (so-called promoters) improve the catalytic performance of these systems under a broad range of reaction conditions (from pure CO to pure CO). Some of these promoters, such as Ga and Zn, can alloy with Cu and their role remains a matter of debate.

Bioevaluation of magnetic mesoporous silica rods: cytotoxicity, cell uptake and biodistribution in zebrafish and rodents.

Mesoporous silica nanoparticles (MSN) characterized by large surface area, pore volume, tunable chemistry, and biocompatibility have been widely studied in nanomedicine as imaging and therapeutic carriers. Most of these studies focused on spherical particles. In contrast, mesoporous silica rods (MSR) that are more challenging to prepare have been less investigated in terms of toxicity, cellular uptake, or biodistribution.

Simultaneous CO reduction and NADH regeneration using formate and glycerol dehydrogenase enzymes co-immobilized on modified natural zeolite.

In this work, the co-immobilization of formate dehydrogenase (FDH) and glycerol dehydrogenase (GlyDH) enzymes is proposed to reduce CO into formic acid, an important chemical intermediate. The reduction of carbon dioxide is carried out by FDH to obtain formic acid, simultaneously, the GlyDH regenerated the nicotinamide cofactor in the reduced form (NADH) by the oxidation of glycerol into dihydroxyacetone. Natural zeolite was selected as immobilization support given its good properties and low cost.

Preparation of carboxylic arylphosphines by hydrolysis of the trifluoromethyl group.

Triarylphosphines substituted with carboxylic and trifluoromethlyl groups have been prepared by the hydrolysis of trifluoromethyl groups using fuming sulfuric acid and boric acid. The reaction has been studied in a set of homoleptic and heteroleptic trifluoromethylated triarylphosphines and offers a new synthetic procedure for the preparation of carboxylic phosphines with a relatively simple methodology. The degree of carboxylation is modulated by the reaction conditions and is sensitive to the substitution pattern of the starting trifluoromethylated phosphines.

Synthesis of triethoxysilylated cyclen derivatives, grafting on magnetic mesoporous silica nanoparticles and application to metal ion adsorption.

The synthesis through click chemistry of triethoxysilylated cyclen derivative-based ligands is described. Different methods were used such as the copper catalyzed Huisgen's reaction, or thiol-ene reaction for the functionalization of the cyclen scaffold with azidopropyltriethoxysilane or mercaptopropyltriethoxysilane, respectively. These ligands were then grafted on magnetic mesoporous silica nanoparticles (MMSN) for extraction and separation of Ni(ii) and Co(ii) metal ions from model solutions.

Standards recommendations for the Earth BioGenome Project.

A global international initiative, such as the Earth BioGenome Project (EBP), requires both agreement and coordination on standards to ensure that the collective effort generates rapid progress toward its goals. To this end, the EBP initiated five technical standards committees comprising volunteer members from the global genomics scientific community: Sample Collection and Processing, Sequencing and Assembly, Annotation, Analysis, and IT and Informatics. The current versions of the resulting standards documents are available on the EBP website, with the recognition that opportunities, technologies, and challenges may improve or change in the future, requiring flexibility for the EBP to meet its goals.

Dimensionality-driven metal-insulator transition in spin-orbit-coupled IrO.

A metal-insulator transition is observed in spin-orbit-coupled IrO thin films upon reduction of the film thickness. In the epitaxially grown samples, the critical thickness ( ∼ 1.5-2.

Methods to determine the quality of acid oils and fatty acid distillates used in animal feeding.

Acid oils and fatty acid distillates are by-products from the refining of edible oils and fats. They are used as feed ingredients, but their highly variable composition sometimes affects the productive parameters of the animals. Thus, their quality control and standardization are necessary.

Scanning agro-industrial wastes as substrates for fungal biopesticide production: Use of Beauveria bassiana and Trichoderma harzianum in solid-state fermentation.

As a waste valorisation option, agro-industrial residues (rice husk, apple pomace, whisky draff, soy fiber, rice fiber, wheat straw, beer draff, orange peel and potato peel) were tested as feasible substrates for fungal conidia production. Solid-state fermentation tests were conducted at laboratory scale (100 g) with Beauveria bassiana or Trichoderma harzianum which conidia are reported to have biopesticide properties. Conidia concentrations with all substrates were at least two orders of magnitude above inoculum except for both fibers, thus demonstrating the possibilities of the proposed waste recovery option.

Atomistic fibrillar architectures of polar prion-inspired heptapeptides.

This article provides the computational prediction of the atomistic architectures resulting from self-assembly of the polar heptapeptide sequences NYNYNYN, SYSYSYS and GYGYGYG. Using a combination of molecular dynamics and a newly developed tool for non-covalent interaction analysis, we uncover the properties of a new class of bionanomaterials, including hydrogen-bonded polar zippers, and the relationship between peptide composition, fibril geometry and weak interaction networks. Our results, corroborated by experimental observations, provide the basis for the rational design of prion-inspired nanomaterials.

Multi-scale analysis of radio-frequency performance of 2D-material based field-effect transistors.

Two-dimensional materials (2DMs) are a promising alternative to complement and upgrade high-frequency electronics. However, in order to boost their adoption, the availability of numerical tools and physically-based models able to support the experimental activities and to provide them with useful guidelines becomes essential. In this context, we propose a theoretical approach that combines numerical simulations and small-signal modeling to analyze 2DM-based FETs for radio-frequency applications.

Hybrid approach to obtain high-quality BaMO perovskite nanocrystals.

A novel hybrid solvothermal approach for perovskite nanocrystal formation accurate control of the hydrolytic process is reported. This new synthetic methodology sets a whole general route to successfully tune the sizes of high-quality BaMO (M = Ti, Zr, and Hf) perovskite nanocrystals. Purely cubic-phase nanocrystals (stable in alcohol media) were obtained using controlled water amounts, combining the well-known aqueous sol-gel process with the classic solvothermal method.

Does carrier velocity saturation help to enhance in graphene field-effect transistors?

It has been argued that current saturation in graphene field-effect transistors (GFETs) is needed to get optimal maximum oscillation frequency ( ). This paper investigates whether velocity saturation can help to get better current saturation and if that correlates with enhanced . We have fabricated 500 nm GFETs with high extrinsic (37 GHz), and later simulated with a drift-diffusion model augmented with the relevant factors that influence carrier velocity, namely: short-channel electrostatics, saturation velocity effect, graphene/dielectric interface traps, and self-heating effects.