The Synthesis of Aromatic Hydrazones as Nitrogen-Containing Prostaglandin Congeners

Severalnitrogen-containingprostaglandincongeners,suchasAHl9437[I]andSQ29548II',werereportedt0beexhibitingpotentactivitiesontissuesclassifiedascontainingTX-sensitivereceptors(TP).Theseledustopreparetheimp0rtantintermediatesIIIbyusingsubstitutedanilinesthroughthenucle0philicoxiranering0peningreacti0n0f2,3-ep0xylbicyclo[3.2.O]hept-6-one'.Inthisarticle,wereport0nthesynthesis0faromatichydraz0nesIVasnitrogen-c0ntainingprostaglandinc0ngenersfromdifferentar0matichydrazinesandIIItosearchforTP-r…     

Side-mode suppression characteristics of phase shifted DFB diode lasers

Previously developed method for analysis of phase shifted DFB lasers is improved by incoporating it with a multi-mode rate equation analysis. The spectral characteristics of phase shifted DFB lasers above threshold can thus be analyzed. This paper considers the side-mode suppression properties of phase shifted DFB laser versus phase shift, phase shift position and kL value under different facet coating conditions.     

Novel Preparation of Methoxy Carbamates of 1-Protected Indole- 3-methylamines as Precursor of Indole-3-methylamine

Indole-3-methylamine (1) has been well demonstrated to be a very useful intermediate as a pharmaceutical building block and starting material for syntheses of phytoalexins.[1] The instability of indole-3-methylamine (1) has undoubtedly restricted its application in synthetic chemistry. Hofmann rearrangement that directly converts carboxamides to alky carbamates in the presence of alcohol required unexceptionally a strong base,[2] which devaluated the possible usefulness of Hofmann rearrangement in preparation of base sensitive amines, especially for the preparation of unstable indole-3-methylamine (1). Herein we would like to report a convenient method for the preparation of alkyl carbamates of 1-protected indole-3-methylamines (4) via the diacetoxyiodobenzene (DIB) promoted Hofmann rearrangement under neutral condition.     

OFDM visible light communication transmitter based on LED array

In this letter, we present a scheme generating OFDM signals in optical domain instead of electrical domain by transmitting subcarrier signals with multiple LEDs. According to the simulation, this scheme can effectively eliminate signal degradation caused by the high peak-to-average power ratio of OFDM signals in traditional transmitter. Computational complexity in digital part of the transmitter can be reduced by using look-uo table. Receiver will stay unchanged.     

Four Families of Nontrivial Product Elements in the Stable Homotopy Groups of Spheres

In this paper, the authors introduce a new effective method to compute the generators of the E1-term of the May spectral sequence. This helps them to obtain four families of non-trivial product elements in the stable homotopy groups of spheres.     

Stereodivergent Synthesis of a-Aminomethyl Cinnamyl Ethers via Photoredox-Catalyzed Radical Relay Reaction

A photocatalytic multi-component radical relay reaction has been developed for the stereodivergent synthesis of both stereoisomers of α-aminomethyl cinnamyl ethers.The radical relay reaction of hydroxylamine derivatives,enol ethers and alkenyl boronic acids in DMSO under white LEDs could lead to E-isomers of α-aminomethyl cinnamyl ethers.The E-isomers could subsequently isomerize to less thermodynamically stable Z-isomers under blue LEDs using toluene as-the co-solvent in a one-pot manner.     

Synthesis of axially chiral oxazoline–carbene coordinated palladium complexes with a N-phenyl framework

A family of tropos ligands bearing a N-heterocyclic carbene and a chiral oxazoline coordination group with a N-phenyl framework were easily prepared,and their coordination behavior with Pd(Ⅱ)acetate was performed,affording a series of axially chiral palladium complexes in good yields.     

Fabrication of flower-like silver nanoparticles for surface-enhanced Raman scattering

The flower-like silver nanoparticles have been synthesized by reducing silver nitrate (AgNO₃) with ascorbic acid (AA) as the reductant and polyvinyl pyrrolidone (PVP) as the capping agent under vigorous stirring. Such flower-like nanoparticles are aggregates of small nanoplates and nanorods. They were tested as substrates for the surface-enhanced Raman scattering (SERS), showing high sensitivity for detecting Rhodamine 6G (R6G) at a concentration as low as 10^-7 mol/L. It has been found that replacing mechanical stirring with ultrasound sonication would drastically change the particle morphology, from flower-like nanoparticles to well-dispersed smaller nanoparticles. Furthermore, when trace amounts of NaCl were added into the reagents, well-dispersed Ag nanoparticles formed even in vigorous stirring. These phenomena can be explained with the diffusion and reactant supply during nucleation and growth of Ag nanoparticles.     

Metal-organic framework derived magnetic nanoporous carbon as an adsorbent for the magnetic solid-phase extraction of chlorophenols from mushroom sample

In this work, a metal-organic framework derived nanoporous carbon(MOF-5-C) was fabricated and modified with Fe_3O_4 magnetic nanoparticles. The resulting magnetic MOF-5-derived porous carbon(Fe_3O_4@MOF-5-C) was then used for the magnetic solid-phase extraction of chlorophenols(CPs) from mushroom samples prior to high performance liquid chromatography–ultraviolet detection. Scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and N_2 adsorption were used to characterize the adsorbent. After experimental optimization, the amount of the adsorbent was chosen as 8.0 mg, extraction time as 10 min, sample volume as 50 m L, desorption solvent as 0.4 m L(0.2 mL×2)of alkaline methanol, and sample p H as 6. Under the above optimized conditions, good linearity for the analytes was obtained in the range of 0.8–100.0 ng g~(-1)with the correlation coefficients between0.9923 and 0.9963. The limits of detection(S/N = 3) were in the range of 0.25–0.30 ng g~(-1), and the relative standard deviations were below 6.8%. The result showed that the Fe3O4@MOF-5-C has an excellent adsorption capacity for the analytes.     

All-solid-state flexible microsupercapacitor based on two-dimensional titanium carbide

MXenes,serving as a novel family of two-dimensional(2D) metal carbides,have attracted great research interest as one of the promising electrode materials due to the unique properties.However,to our best knowledge,the 2D titanium carbide(one kind of MXene) used in constructing microsupercapacitors(MSCs) has not yet been reported to date.To this end,we firstly produce the MXene films on various kinds of substrates including polyethylene terephthalate(PET),silicon oxide film and titanium plate through vacuum-filtrating and subsequent controlled transferring.On this basis,flexible all-solid-state symmetric MSCs on PET substrate based on MXene films are fabricated by micro-fabrication process using polyvinyl alcohol(PVA)/H_2SO_4 as gel electrolyte.The results show that the as-made MSC has an ultrahigh rate performance with the scan rate of up to 1000Vs~(-1) as well as an ultrafast frequency response(τ_0 = 0.5 ms).In addition,the MSC delivers a large volumetric capacitance of 1.44 F cm~(-3),a high volumetric energy density(0.2 mWh cm~(-3) at the current density of 0.288 A cm~(-3) and a good cycling stability.Our research results presented here may pave the way for a new potential application of MXene in micro-power suppliers and micro-energy storage devices.