Access to Enantioenriched Molecules with Diverse Fluorinated Tetrasubstituted Stereocenters Using Hydroxy as Kinetic Resolution Auxiliary Group

Developing a general method affording optically pure fully-substituted carbon molecules bearing various fluorinated groups is highly important but very challenging. Here we show that using secondary OH as the kinetic...

Synthesis of Novel 2-diethylamino-4H-7-(Het) aryl pyrido[1,2-a][1,3,5]triazin-4-ones via a Suzuki Cross-Coupling Reaction of 2-Diethylamino-4H-7-iodopyrido[1,2a][1,3,5]triazin-4-one with (Het) arylboronic Acids in Water

Suzuki cross coupling reaction is one of the most famous organic reactions of the 20th century’s chemistry. It is deemed of as one of the most famous reaction in the field of chemistry. It is a very effective method for making carbon–carbon bonds. It has been extensively utilized in the synthesis of many carbon molecules including the most complex ones.Syntheses of 2-diethylamino-4H-7-(Het) aryl pyrido [1,2-a] [1,3,5] triazin-4-ones are currently under investigation in order to obtain great potentialities in medicinal chemistry of compounds class. The methodology we propose herein is able to produce numerous 2-diethylamino-4H-7-(Het)arylpyrido[1,2-a][1,3,5]triazin-4-one and derivatives that were synthesized, purified and characterized by 1HNMR, 13CNMR, MS techniques. Furthermore, it allows sequential introduction of various substituents into a 2-alkylylamino-4H-7-(Het)arylpyrido[1,2-a][1,3,5]triazin-4-ones ring using a one-pot procedure. The biological evaluation as well as the physico-chemical characterisation of various products are currently under way and will be described elsewhere.

A Taguchi approach for optimization of mass transfer coefficient in metronidazole drug delivery process and activated carbon as a carrier

New strategies have been developed in the drug delivery system in recent years for applications like pharmacokinetics control, pharmacodynamics, undetermined toxicity, immunity, biophysics, and drug efficacy. The loading process was based on adsorption between activated carbon molecules' surfaces and drug molecules dissolved in ethanol at room temperature, where porous activated carbon has great drug delivery characteristics. The current research is studying the effect of the number of parameters including particle size, the weight of drug to the carrier, weight ratio, drug loading and temperature, time, and pH solution on mass transfer coefficient. The Taguchi program's result shows that the optimum point of maximum loading efficiency is 74% when the activated carbon in nanoparticle was in 11.042 nm size, and 985.6013 m2/g surface area weight drug to AC weight ratio is 1.5. The drug process release obtained an optimum point that gives a better value of mass transfer coefficient of 0.0007777 and 0.0003372 cm/hr in the first hour, 37°C, and pH of 1.5 solutions for both metronidazole/macro AC and metronidazole/Nano AC complexes.

The Biomass Waste Pyrolysis for Biopesticide Application

The pyrolysis method has been used in various fields and has attracted the attention of many researchers so that this method can be applied to treat biomass waste. Pyrolysis of biomass occurs through heating a substance with limited oxygen so that the decomposition of complex compounds such as lignocellulose into simpler compounds occurs. The heat energy of the pyrolysis process encourages the oxidation of biomass so that complex carbon molecules break down into carbon and bio-oil. Pyrolysis of biomass for coconut shells, cashew nut shells, and cocoa pod husk was carried out at a temperature of 400–600°C with a flow rate of 6–7°C/min. The content of bio-oil compounds from its biomass based on the analysis of gas chromatography–mass spectroscopy obtained phenolic acid, pyrimidine derivatives, amines, carbamate acids, furans, esters derivatives, pyridine, ketones, furans, and aldehydes that can be used as active compounds for biopesticides.

Regeneration of an Aged Hydrodesulfurization Catalyst by Non-Thermal Plasma: Characterization of Refractory Coke Molecules

This study describes the phenomena involved during the regeneration of an aged industrial hydrodesulfurization catalyst (CoMoP/Al2O3) using a non-thermal plasma at a low temperature (200 °C). The changes occurring during regeneration were studied by characterizing spent, partially, and fully regenerated catalysts by XRD, Raman, TEM spectroscopy, and the coke deposited on the catalyst surface by Laser desorption/ionization time-of-flight mass spectrometry (LDI TOF/MS). The coke is a mixture of several polycyclic molecules, the heaviest with a coronene backbone, containing up to seven sulfur atoms. This kinetic study shows that the oxidation rate depends on the nature of the coke. Hence, explaining the formation of VOCs from heavy polycyclic carbon molecules without complete oxidation to CO2. However, XRD and Raman spectroscopies evidence CoMoO4 formation after a long treatment time, indicating hot spots during the regeneration.

Atom Probe Study of 1-Octadecanethiol Self-Assembled Monolayers on Platinum (111) and (200) Surfaces

Atom probe tomography measurements of self-assembled monolayers of 1-octadecanethiol on platinum tips were performed and their fragmentation behavior under the influence of different laser powers was investigated. The carbon backbone evaporates in the form of small hydrocarbon fragments consisting of one to four carbon atoms, while sulfur evaporates exclusively as single ions. The carbon molecules evaporate at very low fields of 5.9 V/nm, while S requires a considerably higher evaporation field of 23.4 V/nm. With increasing laser power, a weak, but noticeable trend toward larger fragment sizes is observed. No hydrocarbon fragments containing S are detected, indicating that a strong S–Pt bond has formed. The observed surface coverage of S fits well with literature values and is higher for (111)-oriented samples than for (200).

Fischer-Tropsch synthesis using carbon dioxide, water and electricity

The Fischer-Tropsch (FT) synthesis of fuels from CO and H2 lies at the heart of the successful and mature Gas-to-Liquid technology; however its reliance on fossil resources comes with the burden of an undesirable carbon footprint. In contrast, the electroreduction of CO2 (CO2RR) powered by renewable electricity has the potential to produce the same type of fuels, but in a carbon-neutral fashion. To date, only ethylene and ethanol are attainable at reasonable efficiencies and exclusively on copper. Herein, we report that the oxygenated compounds of nickel can selectively electroreduce CO2 to C1 – C6 hydrocarbons with significant yields (Faradaic efficiencies of C3+ up to 6.5%). While metallic Ni only produces hydrogen and methane under CO2RR and FT conditions respectively, we show that polarized nickel (Niδ+) sites facilitate ambient CO2RR via the FT mechanism. The catalysts yield multi-carbon molecules with an unprecedented chain growth probability values (α) up to 0.44, which matches many technical FT synthesis systems. We anticipate that the integration of the herein proposed electrochemical-FT scheme with fuel cells may provide at this seminal stage up to 7% energy efficiency for C3+ hydrocarbons, inaugurating a new era towards the defossilization of the chemical industry.

The vaporization behavior of carbon and hydrogen from the early global magma ocean

<p>Estimating the fluxes and speciation of volatiles during the existence of a global magma ocean is fundamental for understanding the cooling history of the early Earth and for quantifying the volatile budget of the present day. Using first-principles molecular dynamics, we predict the vaporization rate of carbon and hydrogen at the interface between the magma ocean and the hot dense atmosphere, just after the Moon-forming impact. The concentration of carbon and the oxidation state of the melts affect the speciation of the vaporized carbon molecules (e.g., the ratio of carbon dioxide to carbon monoxide), but do not appear to affect the overall volatility of carbon. We find that carbon is rapidly devolatilized even under pressure, while hydrogen remains mostly dissolved in the melt during the devolatilization process of carbon. Thus, in the early stages of the global magma ocean, significantly more carbon than hydrogen would have been released into the atmosphere, and it is only after the atmospheric pressure decreased, that much of the hydrogen devolatilized from the melt. At temperatures of 5000 K (and above), we predict that bubbles in the magma ocean contained a significant fraction of silicate vapor, increasing with decreasing depths with the growth of the bubbles, affecting the transport and rheological properties of the magma ocean. As the temperature cooled, the silicate species condensed back into the magma ocean, leaving highly volatile atmophile species, such as CO<sub>2</sub> and H<sub>2</sub>O, as the dominant species in the atmosphere. Due to the greenhouse nature of CO<sub>2</sub>, its concentration in the atmosphere would have had a considerable effect on the cooling rate of the early Earth.</p>

Investigation of Optical Properties for N and F Doped Triangular Shaped Carbon Molecules

Optical properties of N and F doping triangular shaped carbon molecules have been investigated in theory and experiment. The theoretical results showed that carbon molecules with impurity F and Cl have the same characters with pure carbon. Doping N into pure carbon molecule would change the optical rotation at 589nm. For doping N replacing hydrogen atom structures (N-doping 1 and N-doping 2 molecules), the absorption spectra of them are similar to pure carbon molecule. However, for molecules with impurity N atom in benzene ring (N-doping 3 and N-doping 4 molecules), the peaks of wavelength of absorption spectra shift to long wavelength compared to that of pure carbon molecule. Moreover, the delocalization of molecular orbital (MO) is different from pure carbon molecule, which is caused by the impurity N changing the electrons distribution of benzene ring. We have calculated 3 without H and 4 without H molecules which are removing hydrogen atom in nitrogen atom from N-doping 3 and 4. 3 without H and 4 without H molecules have similar optical properties with pure carbon molecule. The results testified that the impurity N and F would not change the optical properties of carbon molecule if impurity did not change the delocalization of all benzene rings.