Cross-Dehydrogenative Coupling of Secondary Amines with Silanes Catalyzed by Agostic Iridium-NSi Species.

An active catalytic system for the cross-dehydrogenative coupling (CDC) of a wide range of secondary amines with silanes is reported. The iridium(III) derivatives [Ir(H)(X)(κ-NSi)(L)] (NSi = {4,8-dimethylquinoline-2-yloxy}dimethylsilyl; L = coe, X = Cl, ; L = coe, X = OTf, ; L = PCy, X = Cl, ; L = PCy X = OTf, ), which are stabilized by a weak yet noticeable Ir···H-C agostic interaction between the iridium and one of the C-H bonds of the 8-Me substituent of the NSi ligand, have been prepared and fully characterized. These species have proven to be effective catalysts for the CDC of secondary amines with hydrosilanes.

Can Deep Learning Search for Exceptional Chiroptical Properties? The Halogenated [6]Helicene Case.

The relationship between chemical structure and chiroptical properties is not always clearly understood. Nowadays, efforts to develop new systems with enhanced optical properties follow the trial-error method. A large number of data would allow us to obtain more robust conclusions and guide research toward molecules with practical applications.

Recent Advances on the Chemistry of Transition Metal Complexes with Monoanionic Bidentate Silyl Ligands.

The chemistry of transition-metal (TM) complexes with monoanionic bidentate (κ-L,Si) silyl ligands has considerably grown in recent years. This work summarizes the advances in the chemistry of TM-(κ-L,Si) complexes (L=N-heterocycle, phosphine, N-heterocyclic carbene, thioether, ester, silylether or tetrylene). The most common synthetic method has been the oxidative addition of the Si-H bond to the metal center assisted by the coordination of L.

Assessing juvenile swordfish (Xiphias gladius) diet as an indicator of marine ecosystem changes in the northwestern Mediterranean Sea.

To preserve marine biodiversity, we need reliable early warning indicators that inform changes in marine ecosystems. As reliable samplers of mid-trophic level communities, studying the trophodynamics of large pelagic fish can contribute to monitoring these changes. Here, we combined stomach content and stable isotope analyses to reconstruct the diet of juvenile swordfish (Xiphias gladius) in the northwestern Mediterranean Sea, in a time-lapse of almost a decade (2012 and 2020).

Atlantic Oceanic Squids in the "Grey Speciation Zone".

Cryptic species complexes represent an important challenge for the adequate characterization of Earth's biodiversity. Oceanic organisms tend to have greater unrecognized cryptic biodiversity since the marine realm was often considered to lack hard barriers to genetic exchange. Here, we tested the effect of several Atlantic and Mediterranean oceanic barriers on 16 morphospecies of oceanic squids of the orders Oegopsida and Bathyteuthida using three mitochondrial and one nuclear molecular marker and five species delimitation methods.

Correction: Iridium-(κ-NSi) catalyzed dehydrogenation of formic acid: effect of auxiliary ligands on the catalytic performance.

Correction for 'Iridium-(κ-NSi) catalyzed dehydrogenation of formic acid: effect of auxiliary ligands on the catalytic performance' by Alejandra Gomez-España , , 2023, , 6722-6729, https://doi.org/10.1039/d3dt00744h.

Multi-stimuli-responsive chitosan-functionalized magnetite/poly(ε-caprolactone) nanoparticles as theranostic platforms for combined tumor magnetic resonance imaging and chemotherapy.

Chitosan-functionalized magnetite/poly(ε-caprolactone) nanoparticles were formulated by interfacial polymer disposition plus coacervation, and loaded with gemcitabine. That (core/shell)/shell nanostructure was confirmed by electron microscopy, elemental analysis, electrophoretic, and Fourier transform infrared characterizations. A short-term stability study proved the protection against particle aggregation provided by the chitosan shell.

Correction: Iridium-(κ-NSi) catalyzed dehydrogenation of formic acid: effect of auxiliary ligands on the catalytic performance.

Correction for 'Iridium-(κ-NSi) catalyzed dehydrogenation of formic acid: effect of auxiliary ligands on the catalytic performance' by Alejandra Gomez-España , , 2023, https://doi.org/10.1039/d3dt00744h.

Iridium-(κ-NSi) catalyzed dehydrogenation of formic acid: effect of auxiliary ligands on the catalytic performance.

The iridium(III) complexes [Ir(H)(Cl)(κ-NSi)(κ-bipy)] (2) and [Ir(H)(OTf)(κ-NSi)(κ-bipy)] (3) (NSi = {4-methylpyridine-2-yloxy}ditertbutylsilyl) have been synthesized and characterized including X-ray studies of 3. A comparative study of the catalytic activity of complexes 2, 3, [Ir(H)(OTf)(κ-NSi)(coe)] (4), and [Ir(H)(OTf)(κ-NSi)(PCy)] (5) (0.1 mol%) as catalysts precursors for the solventless formic acid dehydrogenation (FADH) in the presence of EtN (40 mol%) at 353 K has been performed.

Genome skimming elucidates the evolutionary history of Octopoda.

Phylogenies for Octopoda have, until now, been based on morphological characters or a few genes. Here we provide the complete mitogenomes and the nuclear 18S and 28S ribosomal genes of twenty Octopoda specimens, comprising 18 species of Cirrata and Incirrata, representing 13 genera and all five putative families of Cirrata (Cirroctopodidae, Cirroteuthidae, Grimpoteuthidae, Opisthoteuthidae and Stauroteuthidae) and six families of Incirrata (Amphitretidae, Argonautidae, Bathypolypodidae, Eledonidae, Enteroctopodidae, and Megaleledonidae) which were assembled using genome skimming. Phylogenetic trees were built using Maximum Likelihood and Bayesian Inference with several alignment matrices.

Mechanism Insights into the Iridium(III)- and B(CF)-Catalyzed Reduction of CO to the Formaldehyde Level with Tertiary Silanes.

The catalytic system [Ir(CFCO)(κ-NSi)] [; NSi = (4-methylpyridin-2-yloxy)dimethylsilyl]/B(CF) promotes the selective reduction of CO with tertiary silanes to the corresponding bis(silyl)acetal. Stoichiometric and catalytic studies evidenced that species [Ir(CFCOO-B(CF))(κ-NSi)] (), [Ir(κ-NSi)][HB(CF)] (), and [Ir(HCOO-B(CF))(κ-NSi)] () are intermediates of the catalytic process. The structure of has been determined by X-ray diffraction methods.

Parasites and prey of the nursehound shark Scyliorhinus stellaris (Linnaeus, 1758): Insights into hidden trophic web interactions in the Mediterranean Sea.

The metazoan parasite community and the stomach contents of the nursehound shark Scyliorhinus stellaris from the Gulf of Naples (central Mediterranean Sea) were studied. The nursehound shark harboured a poor parasite community composed of a species of gill monogenean (Hexabothrium appendiculatum) and three intestinal cestode taxa (Acanthobothrium coronatum and two unidentified species of the genera Yamaguticestus and Scyphophyllidium), all represented by adult stages. Hosts were mostly parasitized by individuals of A.

Synthesis and Characterization of Ir-(κ-NSi) Species Active toward the Solventless Hydrolysis of HSiMe(OSiMe).

The reaction of [IrH(Cl)(κ-NSi)(coe)] () with 1 equiv of PCy (or PHBu) gives the species [IrH(Cl)(κ-NSi)(L)] (L = PCy, ; PHBu, ), which reacts with 1 equiv of AgOTf to afford [IrH(OTf)(κ-NSi)(L)] (L = PCy, and PHBu, ). Complexes , , , and have been characterized by means of NMR spectroscopy and HR-MS. The solid-state structures of complexes , and have been determined by X-ray diffraction studies.

Collecting and Culturing Lineus sanguineus to Study Nemertea WBR.

Whole-body regeneration, the ability to reconstruct complete individuals from small fragments, is rare among ribbon worms (phylum Nemertea) but present in the pilidiophoran species Lineus sanguineus. This species can regenerate complete individuals from a tiny midbody section, and even from a quarter of a piece, provided it retains a fragment of a lateral nerve cord. While a few other unrelated species of ribbon worms are also excellent regenerators, L.

Dehydrogenation of formic acid using iridium-NSi species as catalyst precursors.

Using a low loading of the iridium(III) complexes [Ir(CFSO)(κ-NSi)] (1) (NSi = (4-methylpyridin-2-yloxy)diisopropylsilyl) and [{Ir(κ-NSi)}(μ-CFSO)] (2) (NSi = (4-methylpyridin-2-yloxy)dimethylsilyl) in the presence of EtN, it has been possible to achieve the solventless selective dehydrogenation of formic acid. The best catalytic performance (TOF ≈ 2900 h) has been achieved with 2 (0.1 mol%) and EtN (40 mol% to FA) at 373 K.

A Tri-Stimuli Responsive (Maghemite/PLGA)/Chitosan Nanostructure with Promising Applications in Lung Cancer.

A (core/shell)/shell nanostructure (production performance ≈ 50%, mean diameter ≈ 330 nm) was built using maghemite, PLGA, and chitosan. An extensive characterization proved the complete inclusion of the maghemite nuclei into the PLGA matrix (by nanoprecipitation solvent evaporation) and the disposition of the chitosan shell onto the nanocomposite (by coacervation). Short-term stability and the adequate magnetism of the nanocomposites were demonstrated by size and electrokinetic determinations, and by defining the first magnetization curve and the responsiveness of the colloid to a permanent magnet, respectively.

Phylogenomics illuminates the evolution of bobtail and bottletail squid (order Sepiolida).

Bobtail and bottletail squid are small cephalopods with striking anti-predatory defensive mechanisms, bioluminescence, and complex morphology; that inhabit nektobenthic and pelagic environments around the world's oceans. Yet, the evolution and diversification of these animals remain unclear. Here, we used shallow genome sequencing of thirty-two bobtail and bottletail squids to estimate their evolutionary relationships and divergence time.

Engineering of stealth (maghemite/PLGA)/chitosan (core/shell)/shell nanocomposites with potential applications for combined MRI and hyperthermia against cancer.

(Maghemite/poly(d,l-lactide-co-glycolide))/chitosan (core/shell)/shell nanoparticles have been prepared reproducibly by nanoprecipitation solvent evaporation plus coacervation (production performance ≈ 45%, average size ≈ 325 nm). Transmission electron microscopy, energy dispersive X-ray spectroscopy, electrophoretic determinations, and X-ray diffraction patterns demonstrated the satisfactory embedment of iron oxide nanocores within the solid polymer matrix and the formation of an external shell of chitosan in the nanostructure. The adequate magnetic responsiveness of the nanocomposites was characterized in vitro by hysteresis cycle determinations and by visualization of the nanosystem under the influence of a 0.

Origin of the Ir-Si bond shortening in Ir-NSiN complexes.

The Ir-Si bond distances reported for Ir-(fac-κ3-NSiNOPy) and Ir-(fac-κ3-NSiN4MeOPy) species (NSiNOPy = bis(pyridine-2-yloxy)methylsilyl and NSiN4MeOPy = bis(4-methyl-pyridine-2-yloxy)methylsily) are in the range of 2.220-2.235 Å.

Potentially handicapped but otherwise functional: Malformations in prey capture tools show no impacts on octopus life.

Larval mortality is a keystone ecological factor for many benthic octopus since it mostly occurs before their settlement in the sea bottom as benthic juveniles. The literature had revealed that records of adult animals with morphological abnormalities (teratologies) are fewer in species with complex life cycle than in those with direct development. This is a direct consequence of the morphological, physiological, and development challenges that the transition from the larval to the adult morphology represents.

Gemcitabine-Loaded Magnetically Responsive Poly(-caprolactone) Nanoparticles against Breast Cancer.

A reproducible and efficient interfacial polymer disposition method has been used to formulate magnetite/poly(-caprolactone) (core/shell) nanoparticles (average size ≈ 125 nm, production performance ≈ 90%). To demonstrate that the iron oxide nuclei were satisfactorily embedded within the polymeric solid matrix, a complete analysis of these nanocomposites by, e.g.

2-Pyridone-stabilized iridium silylene/silyl complexes: structure and QTAIM analysis.

Iridium(iii) complexes of the general formula [Ir(X)(κ2-NSiiPr2)2] (NSiiPr2 = (4-methyl-pyridine-2-yloxy)diisopropylsilyl; X = Cl, 3; CF3SO3, 5; CF3CO2, 6) have been prepared and fully characterized, including X-ray diffraction studies and theoretical calculations. The presence of isopropyl substituents at the silicon atom favours the monomeric structure found in complexes 3 and 5. The short Ir-Si bond distances (2.

First steps in the formulation of praziquantel nanosuspensions for pharmaceutical applications.

Praziquantel (PZQ), a broad spectrum anthelmintic drug, cannot be found in acceptable dosage forms for elderly patients, paediatric patients, and for veterinary use. In fact, very little has been done up to now in the formulation of liquid dosage forms, being they always formulated for parenteral administration. To beat this important challenge, it was accomplished a comprehensive analysis of the influence of two elementary physicochemical aspects, i.