Bakerlin6021

Z Iurium Wiki

Verze z 23. 9. 2024, 17:18, kterou vytvořil Bakerlin6021 (diskuse | příspěvky) (Založena nová stránka s textem „The reactivity of the triflate functionalized iridapentalene 1, [Ir[double bond, length as m-dash]CHC(CH2C(CO2Me)2CH2)[double bond, length as m-dash]CC[dou…“)
(rozdíl) ← Starší verze | zobrazit aktuální verzi (rozdíl) | Novější verze → (rozdíl)

The reactivity of the triflate functionalized iridapentalene 1, [Ir[double bond, length as m-dash]CHC(CH2C(CO2Me)2CH2)[double bond, length as m-dash]CC[double bond, length as m-dash]CHC(OTf)[double bond, length as m-dash]CH(CO)(PPh3)2]OTf, with C-, N-, O- and S-centered neutral nucleophiles was studied, leading to the isolation of a wide array of irida-carbolong derivatives. As an extension, a polycyclic complex with a rare six-fused-ring structure was constructed. selleckchem This strategy provides a new route for the construction of functionalized metallaaromatic complexes, and the resulting iridacycles exhibit broad spectral absorption ranges, making them potential photoelectric materials.Hyperthermal oxidation of silicon is envisaged to be an alternative to silicon-on-insulator (SOI) waveguide fabrication for photonic integrated circuit (PIC) devices, and thus the local oxidation of silicon (LOCOS) technique has attracted attention. In this article, starting with the thermodynamic insights into the Deal-Grove model for defining the thermal oxidation, we model the Henry's law constant in the silicon oxidation process with the ensemble contributions of thermodynamic and chemical energies, and extract an empirical model with the published statistical data. Then, the simulations show the dramatic temperature/time dependences of Henry's constant, and the different effects of the thermodynamic and chemical energies. Systematic simulations of the temperature/time dependences of both the growth rate and thickness of oxide are carried out where the temperature dependence of the oxidant diffusivity is also considered. Consequently, the simulation results from the two models astonishingly agree with each other. Typically, at 1100 °C, with a 3 h oxidation time, 2.10 and 1.34 μm SiO2 layers can be grown with the thermodynamic model under two diffusivity models, while with the empirical one, the two extreme cases can grow 2.10 and 1.28 μm SiO2 layers, respectively.Monolayer semiconducting two-dimensional (2D) materials are strongly emerging materials for exploring the spin-valley coupling effect and fabricating novel optoelectronic devices due to their unique structural symmetry and band structures. Due to their atomic thickness, their excitonic optical response is highly sensitive to the dielectric environment. In this work, we present a novel approach to reversibly modulate the optical properties of monolayer molybdenum disulfide (MoS2) via changing the dielectric properties of the substrate by laser irradiation and thermal annealing. We chose LiNbO3 as the substrate and recorded the PL spectra of monolayer MoS2 on LiNbO3 substrates with positive (P+) and negative (P-) ferroelectric polarities. A distinct PL intensity of the A peak was observed due to opposite doping by surface charges. Under light irradiation, the PL intensity of monolayer MoS2 on P+ Fe2O3-doped LiNbO3 gradually decreased with time due to the reduction of intrinsic p-doping, which originated from the drift of photo-excited electrons under a spontaneous polarization field and accumulation on the surface. The PL intensity was found to be restored by thermal annealing which could erase the charge redistribution. This study provides a strategy to reversibly modulate the optical properties of monolayer 2D materials on top of ferroelectric materials.Ligands dramatically affect the electronic structure of gold nanoclusters (NCs) and provide a useful handle to tune the properties required for nanomaterials that have high performance for important functions like catalysis. Recently, questions have arisen about the nature of the interactions of hydride and halide ligands with Au NCs hydride and halide ligands have similar effects on the absorption spectra of Au9 NCs, which suggested that the interactions of the two classes of ligands with the Au core may be similar. Here, we elucidate the interactions of halide and hydride ligands with phosphine-protected gold clusters via theoretical investigations. The computed absorption spectra using time-dependent density functional theory are in reasonable agreement with the experimental spectra, confirming that the computational methods are capturing the ligand-metal interactions accurately. Despite the similarities in the absorption spectra, the hydride and halide ligands have distinct geometric and electronic effects. The hydride ligand behaves as a metal dopant and contributes its two electrons to the number of superatomic electrons, while the halides act as electron-withdrawing ligands and do not change the number of superatomic electrons. Clarifying the binding modes of these ligands will aid in future efforts to use ligand derivatization as a powerful tool to rationally design Au NCs for use in functional materials.The new isonitrile-μ-carbido complexes [WPt(μ-C)Br(CNR)(PPh3)(CO)2(Tp*)] (R = C6H2Me3-2,4,6, C6H3Me2-2,6; Tp* = hydrotris(dimethylpyrazolyl)borate) rearrange irreversibly in polar solvents to provide the first examples of iminoketenylidene (CCNR) complexes.To activate methane at low or medium temperatures is a difficult task and a pre-requisite for the conversion of this light alkane into high value chemicals. Herein, we report the preparation and characterizations of novel SnOx/Cu2O/Cu(111) interfaces that enable low-temperature methane activation. Scanning tunneling microscopy identified small, well-dispersed SnOx nanoclusters on the Cu2O/Cu(111) substrate with an average size of 8 Å, and such morphology was sustained up to 450 K in UHV annealing. Ambient pressure X-ray photoelectron spectroscopy showed that hydrocarbon species (CHx groups), the product of methane activation, were formed on SnOx/Cu2O/Cu(111) at a temperature as low as 300 K. An essential role of the SnOx-Cu2O interface was evinced by the SnOx coverage dependence. Systems with a small amount of tin oxide, 0.1-0.2 ML coverage, produced the highest concentration of adsorbed CHx groups. Calculations based on density functional theory showed a drastic reduction in the activation barrier for C-H bond cleavage when going from Cu2O/Cu(111) to SnOx/Cu2O/Cu(111). On the supported SnOx, the dissociation of methane was highly exothermic (ΔE∼-35 kcal mol-1) and the calculated barrier for activation (∼20 kcal mol-1) could be overcome at 300-500 K, target temperatures for the conversion of methane to high value chemicals.Free-standing stable two-dimensional (2D) boron monolayers, i.e., borophenes, usually settle into triangular lattices with different ratios of monoatomic vacancies. However, a stable polymorph can be drastically distinct from a free-standing one upon charge doping or on a substrate, as evidenced by the free-standing unstable hexagonal borophene that was prepared on the Al(111) substrate [Sci. Bull., 2018, 63, 282]. Moreover, 2D borophenes prefer to be oxidized to form more stable borophene oxides under ambient conditions. In this work, with the help of first-principles calculations, we propose a stable borophene oxide (t-B2O) through oxidizing the free-standing unstable T-borophene. More interestingly, t-B2O is a topological nodal-ring semimetal protected by in-plane mirror symmetry and characterized by a topological index. The energy fluctuation of the nodal ring is small and no extraneous bands are entangled with the nodal ring around the Fermi level. Two tight-binding models are developed to elucidate the orbital interactions and the formation of the nodal ring. Our work not only discovers a new ideal 2D topological nodal-ring semimetal, but the method used here also provides a fresh view in the search for 2D materials.A high loading of Mn(ii)-metalated porphyrin was achievable in a 2D porphyrin-based Mn-MOF induced by an ionic liquid. The excellent stability, sufficient redox potential, atomically dispersed porphyrin Mn(ii) sites, desired CO2 affinity, high visible light-harvesting and efficient charge separation, endow this MOF with the overall photocatalytic conversion of CO2 to CH4 in gas-solid conditions.A new method for the fluorine-18 labelling of trifluoromethyl ketones has been developed. This method is based on the conversion of a-COCF3 functional group to a difluoro enol silyl ether followed by halogenation and fluorine-18 labelling. The utility of this new method was demonstrated by the synthesis of fluorine-18 labelled neutrophil elastase inhibitors, which are potentially useful for detection of inflammatory disorders.The quest to maximize therapeutic efficiency in cancer treatment requires innovative delivery nanoplatforms capable of employing different modules simultaneously. Combination therapy has proven to be one of the best anticancer strategies so far. Herein, we have developed a lipid-encapsulated nanoplatform that combines chemotherapy with photoresponsive gas therapy for colon cancer treatment. Carbon monoxide releasing molecules (CORMs) and vitamin E analogues (pure/pegylated α-tocopheryl succinate; α-TOS) were co-loaded into the lipid layer with core-shell upconversion nanoparticles (UCNPs), which converted 808 nm light to 360 nm photons to trigger CO release at the tumor site. This folic acid (FA)-targeting nanomedicine (Lipid/UCNP/CORM/α-TOS/FA LUCTF) possessed a cancer-targeting ability and a light-triggered CO release ability for synergistic apoptosis of HCT116 cells via enhanced ROS generation and mitochondrial membrane breaking. In vivo data have confirmed the significantly enhanced therapeutic efficacy of LUCTF without any significant biosafety issues after intravenous administration. Thus, nanomedicine LUCTF represents a novel way for efficient cancer therapy via combining locally released CO and a compatible chemotherapeutic agent (e.g. α-TOS).In this work, we have implemented a polymerase and endonuclease synergetic amplification reaction in living cells for intracellular miRNA imaging by using biomineralized ZIF-8 NPs.A scaffold, constructed from a bi-layer silk fibroin skeleton (BSFS) and a bladder acellular matrix hydrogel (BAMH) encapsulated with adipose-derived stem cells (ASCs), was developed for bladder augmentation in a rat model. The BSFS, prepared from silk fibroin (SF), had good mechanical properties that allowed it to maintain the scaffold shape and be used for stitching. The prepared BAM was digested by pepsin and the pH was adjusted to harvest the BAMH that provided an extracellular environment for the ASCs. The constructed BSFS-BAMH-ASCs and BSFS-BAMH scaffolds were wrapped in the omentum to promote neovascularization and then used for bladder augmentation; at the same time, a cystotomy was used as the condition for the control group. Histological staining and immunohistochemical analysis confirmed that the omentum incubation could promote scaffold vascularization. Hematoxylin and eosin and Masson's trichrome staining indicated that the BSFS-BAMH-ASCs scaffold regenerated the bladder wall structure. In addition, immunofluorescence analyses confirmed that the ASCs could promote the regeneration of smooth muscle, neurons and blood vessels and the restoration of physiological function. These results demonstrated that the BSFS-BAMH-ASCs may be a promising scaffold for promoting bladder wall regeneration and the restoration of physiological function of the bladder in a rat bladder augmentation model.

Autoři článku: Bakerlin6021 (Harder Franks)