Radical Formation Research Articles

Atmospheric propane (C3H8) column retrievals from ground-based FTIR observations in Xianghe, China

Abstract. Propane (C3H8) is an important trace gas in the atmosphere, as it is a proxy for oil and gas production and has a significant impact on atmospheric chemical reactions related to the hydroxyl radical and tropospheric ozone formation. In this study, solar direct absorption spectra near 2967 cm−1 recorded by a ground-based Fourier transform infrared spectrometer (FTIR) were applied to retrieve C3H8 total columns between June 2018 and July 2022 in Xianghe in north China. The systematic and random uncertainties of the C3H8 column retrieval are estimated to be 18.4 % and 18.1 %, respectively. The mean and standard deviation of the C3H8 columns derived from the FTIR spectra in Xianghe are 1.80 ± 0.81 (1σ) × 1015 molec. cm−2. Good correlations are found between C3H8 and other non-methane hydrocarbons, such as C2H6 (R=0.84) and C2H2 (R=0.79), as well as between C3H8 and CO (R=0.72). However, the correlation between C3H8 and CH4 is relatively weak (R=0.45). Moreover, the FTIR C3H8 measurements in Xianghe are also compared against MkIV measurements at several sites around the world. The new FTIR measurements in Xianghe provide us with insight into C3H8 column variations and the underlying processes in north China.

Room-temperature selective cyclodehydrogenation on Au(111) via radical addition of open-shell resonance structures

Cyclodehydrogenation is an important ring-formation reaction that can directly produce planar-conjugated carbon-based nanomaterials from nonplanar molecules. However, inherently high C–H bond energy necessitates a high temperature during dehydrogenation, and the ubiquity of C − H bonds in molecules and small differences in their bond energies hinder the selectivity of dehydrogenation. Here, we report a room-temperature cyclodehydrogenation reaction on Au(111) via radical addition of open-shell resonance structures and demonstrate that radical addition significantly decreases cyclodehydrogenation temperature and further improves the chemoselectivity of dehydrogenation. Using scanning tunneling microscopy and non-contact atomic force microscopy, we visualize the cascade reaction process involved in cyclodehydrogenation and determine atomic structures and molecular orbitals of the planar acetylene-linked oxa-nanographene products. The nonplanar intermediates observed during progression annealing, combined with density functional theory calculations, suggest that room-temperature cyclodehydrogenation involves the formation of transient radicals, intramolecular radical addition, and hydrogen elimination; and that the high chemoselectivity of cyclodehydrogenation arises from the reversibility and different thermodynamics of radical addition step.

Research on the Influence of Fault Structure on Physical and Chemical Structure of Coking Coal During Spontaneous Combustion

ABSTRACT The spontaneous combustion tendency and oxidation combustion properties of coking coal in fault fracture zone and primary coking coal are different. Accordingly, this study uses Thermogravimetric analysis, in-situ Fourier transform infrared spectroscopy, Scanning electron microscope, low-temperature N2 adsorption and Electron spin resonance techniques were used to study the difference of macroscopic and microscopic structural characteristics between coking coal and primary coking coal in fault fracture zone. The results show that: The oxygen absorption capacity of coking coal in fault fracture zone is enhanced and the thermogravimetric characteristic temperature is advanced, and the ignition point temperature is advanced by 5.36°C; the maximum weight loss temperature of coking coal in fault fracture zone is 3.32°C lower than that of primary coking coal. The apparent activation energy of coking coal in oxidation stage and pyrolytic combustion stage decreased by 4.88 and 5.03 kJ/mol, respectively. Compared with primary coking coal, the pore structure of coking coal in fault fracture zone is more complex, which increases the roughness of coal surface and is conducive to oxygen adsorption. In addition, fault tectonics promotes the separation and cracking of oxygen-containing functional groups into small molecules, and the polycondensation of aliphatic hydrocarbon structure promotes the formation of active free radicals, thus promoting spontaneous combustion. This study provides an important reference and theoretical support for further understanding of the structural evolution and oxidation kinetics of highly metamorphic coking coal induced by fault tectonics, which is helpful for fire prevention and control in fault structure-developed mining areas and safe production of coal industry.

Hydroxylated SiO2-modified {0 0 1}-TiO2 nanosheets as a surface multifunctional photocatalyst for enhanced degradation of gaseous toluene

The relatively weak activity and serious deactivation of anatase TiO2 nanosheet catalysts with highly exposed {001} facets ({001}-TiO2) limits its wide application in photocatalytic degradation of gaseous pollutants. Herein, we propose a hybrid photocatalyst composed of {001}-TiO2 and SiO2 with numerous hydroxyl groups (denoted as {001}-TiO2/HO-SiO2). The catalyst showed excellent performance for gaseous toluene degradation under UV illumination, with 99.2 % removal efficiency and 204.7 μmol L−1 CO2 yield (about 85.9 % mineralization efficiency) within 120 min. It also demonstrated superior durability over five consecutive cycles of toluene photodegradation. The modification of HO–SiO2 on {001}-TiO2 facilitate the selective adsorption of toluene on the catalyst surface by H-bonding interaction, and make the major poisoning species, benzoic acid, easily desorb from the surface, reducing the catalyst inactivation. Most importantly, we found that the formed TiOSi bond promotes the separation of photogenerated electron–hole pairs, and provides abundant available electrons for the formation of reactive oxygen radicals and the left holes for the conversion of toluene to benzyl radicals or oxidation of H2O to hydroxyl radicals, which results in the improved activity. This study highlights the importance of the introduction of secondary components with special functions on TiO2, which is helpful for the design of photocatalysts with high performance and anti-deactivation ability for treatment of volatile organic compounds.

Mechanistic studies on the oxidation reaction of n-pentane

The oxidation reaction mechanism of n-pentane is investigated using density functional theory and transition state theory as a case study to elucidate the combustion characteristics of liquids with low boiling points. This study divides the oxidation reaction of n-pentane into four steps. First, n-pentane decomposes to form n-pentyl radicals C5H11 and H, CH3 and C4H9, and C2H5 and C3H7 radicals. Second, n-pentane primarily undergoes H-abstraction reactions with H, CH3, C2H5, and C3H7 radicals to form the C5H11 radicals. Subsequently, C5H11 radicals react with O2 in an addition reaction to form n-pentyl peroxy radicals ROO. Finally, ROO radical undergoes internal H-atom transfer to form hydroperoxy pentyl radicals QOOH, which then undergoes cyclization and bond scission to produce cyclic ethers, alkenes, aldehydes, OH radicals, and HO2 radicals. Results indicate that n-pentane readily decomposes into C2H5 and C3H7 radicals, with a bond dissociation energy of 367.1 KJ/mol. The H-abstraction reactions involving H and CH3 radicals have the fastest rates, which require the lowest energy barriers of 21.6 and 41.9 KJ/mol, respectively. The reaction between C5H11 and O2 is a barrierless addition reaction. The oxidation of n-pentane, which leads to the formation of 2-methyloxirane and OH radicals, exhibits the fastest reaction rate.

Natural diterpene carrier-free hydrogel enhances antigen presentation and intensifies T cell activation for tumor immunotherapy

Although immunotherapy has revolutionized cancer treatment, the low immunogenicity, insufficient T cells intratumoral infiltration and defective antigen presentation in the “cold” tumor microenvironment limit its clinical application. To address this challenge, enlightened by the clinical combined application of antitumor herb medicines, we developed a carrier-free hydrogel KEEM by integrating multiple natural active lipophilic components with manganese ions into a natural co-assembled ternary system. The KEEM hydrogel induced the formation of hydroxyl radicals by Fenton-like reactions, leading to apoptosis, while simultaneously inducing tumor cell ferroptosis through the system xc−-GSH-GPX4 axis. Subsequent release of damage-associated molecular patterns (DAMPs) proved the emergence of immunogenic cell death (ICD). Additionally, manganese ions could directly activate the cGAS-STING pathway, further amplifying the immunostimulatory effects. This synergistic effect promoted dendritic cell maturation thus enhancing antigen presentation, and mediating the change of tumor microenvironment (TME) from “cold” to “hot”. In hepatoma ascites and melanoma models, KEEM combined with immune checkpoint blockade and adoptive T cell therapy respectively demonstrated promising anti-tumor effects in vivo, meanwhile showing excellent biocompatibility and biosafety. Thus, the combination of this multi-diterpenoids carrier-free hydrogel with immunotherapy offers a new strategy for clinical immune-refractory tumor treatment.

Piezo-modulated interface field facilitating hydroxyl radical formation of SrTiO3/ZnO heterojunction for water purification

Piezo-modulated interface engineering is an effective method for tuning the charge transfer process to enhance piezocatalytic dynamics. In this study, SrTiO3/ZnO heterojunctions were successfully synthesized via hydrothermal methods to degrade carbamazepine in water. The optimal SrTiO3/ZnO-5 % sample exhibited a remarkable 99.9 % degradation efficiency of carbamazepine within 60 min under ultrasonic vibration. The piezocatalytic reaction rate (k value = 0.0746 min−1) was 4.63 times and 10.97 times higher than that of pure SrTiO3 and pure ZnO, respectively. Reactive species scavenger tests, electron paramagnetic resonance techniques, and bands gap analysis revealed that the enhanced activity can be attributed to the construction of an interfacial electric field in SrTiO3/ZnO heterojunctions and the modification of an internal piezoelectric polarized field. This allowed charge redistribution and transport across the SrTiO3/ZnO heterojunction interface, and facilitated the generation of hydroxyl radicals (HO•) through simultaneous hole oxidation and electron reduction. This study provides a comprehensive mechanistic understanding about piezoelectric heterojunctions in the catalytic redox reactions, and offers valuable insights for designing more effective piezoelectric heterojunctions for the degradation of pharmaceutical organic pollutants.

“The Revival of Islam”: a French view of the Islamic Revolution in Iran

In this article, the author investigates the responses of French diplomats and experts to the events occurring in Iran during 1978–1979 and their consequences. This analysis is conducted primarily in the context of the rising prominence of religious considerations in international relations. To this end, the author draws on materials from the archives of the French Ministry of Foreign Affairs. In France, the dual nature of these events was acknowledged. Firstly, there was a notable “re-Islamisation” of the populations in Muslim countries. In many of them, Islam became an influential factor in the formation of national identities after independence, serving to unify and stabilise communities. Secondly, French diplomats emphasised that while religion played a part in these developments, it was not the sole driving force. Rather, it was employed by local leaders as a political tool to advance their own agendas. The French experts demonstrated a tendency to overestimate the degree of Western influence on educated and wealthy sections of Muslim populations, while simultaneously underestimating the capacity of nationally oriented Islamic leaders and movements to modernise their respective countries. Furthermore, these experts also underestimated the ability of these leaders and movements to defend their right to development in accordance with their own customs and traditions. It is notable that many of the conclusions drawn by French diplomats at the turn of the 1970s and 1980s do not align with the contemporary interpretations of the French authorities. A review of the French Foreign Ministry notes from 1978 to 1979 revealed no mention of the issue of Islamic influence and its radical form in the Maghreb and the Middle East on the Muslim community in France.

Bioinspired Photothermal Metal-Organic Framework Cocrystal with Ultra-Fast Water Transporting Channels for Solar-Driven Interfacial Water Evaporation.

Herein, a bioinspired metal-organic framework (MOF) cocrystal produced from the co-assembly of a MOF [Ni3(hexaiminobenzene)2, Ni3(HIB)2] and p-chloranils (CHLs) is reported. Because of the 2D conjugation nature and the formation of persistent anion radicals, this cocrystal shows an excellent photothermal property, and is further used as an absorber in solar-driven interfacial water evaporation. The solar-driven interfacial water evaporation rate (4.04 kg m-2 h-1) is among the best compared with those of previously reported photothermal materials. Molecular dynamics simulation results suggested that the rotating of the CHL molecules relative to the MOF planes tuned the pore size to enable the ultra-fast water transporting, and thus ultra-high water transporting rates (1.11 × 1011 and 3.21 × 1011 H2O s-1 channel-1 at 298.2 and 323.0 K, respectively) for layered cocrystal structures, that are much higher than that of aquaporins (≈1.1 × 1010 H2O s-1 channel-1 at 298.2 K), are observed. The superior solar-driven water evaporation performance is thus attributed to the synergistic effect of the ultra-fast water transporting pores together with the excellent photothermal property of the cocrystal. This research provided a biomimetic strategy of rational design and production of charge transfer cocrystals to modulate their pores and photothermal properties for solar-driven interfacial water evaporation.

Towards a Politics of Transgression in Environmental Education Research: Meta-review of a T-Learning Research ‘Archive’

Abstract The need for more radical forms of learning-centred transformation is increasingly recognised in transformations to sustainability. Yet these approaches to learning remain under-developed and undertheorised especially from a politics and environmental education research perspective. This paper offers a review of an emerging politics of transgression in environmental education research, as developed through an extensive T-learning (transgressive learning in times of climate change) knowledge co-production research programme, spanning eight years, and continuing. The ongoing problem that the research programme seeks to address is how to do transgressive learning in/as environmental education research in times where the fall out of coloniality and fossil capital collide in an increasingly regressive political landscape which Akomolafe and Ladha (2017, pg. 820) describe as “the deadening ideology of late-stage capitalism and its corollaries of patriarchy, rationalism, white supremacy and anthropocentrism.” Through the paper, I seek to highlight a “low theory” (Wark, 2021) of transgressive politics in environmental education research, embodied in practices of transgressive politics as movement in co-engaged T-learning research, which I illuminate through a meta-reflective curational process from the ‘archive’ or T-learning knowledge commons collection.

Photocatalytic H2O2 production over boron-doped g-C3N4 containing coordinatively unsaturated FeOOH sites and CoOx clusters

Graphitic carbon nitride (g-C3N4) has gained increasing attention in artificial photosynthesis of H2O2, yet its performance is hindered by sluggish oxygen reduction reaction (ORR) kinetics and short excited-state electron lifetimes. Here we show a B-doped g-C3N4 (BCN) tailored with coordinatively unsaturated FeOOH and CoOx clusters for H2O2 photosynthesis from water and oxygen without sacrificial agents. The optimal material delivers a 30-fold activity enhancement compared with g-C3N4 under visible light, with a solar-to-chemical conversion efficiency of 0.75%, ranking among the forefront of reported g-C3N4-based photocatalysts. Additionally, an electron transfer efficiency reaches 34.1% for the oxygen reduction reaction as revealed by in situ microsecond transient absorption spectroscopy. Experimental and theoretical results reveal that CoOx initiates hole–water oxidation and prolongs the electron lifetime, whereas FeOOH accepts electrons and promotes oxygen activation. Intriguingly, the key to the direct one-step two-electron reaction pathway for H2O2 production lies in coordinatively unsaturated FeOOH to adjust the Pauling-type adsorption configuration of O2 to stabilize peroxide species and restrain the formation of superoxide radicals.

Phototriggered Hydrogen Persulfide Donors via Hydrosulfide Radical Formation Enhancing the Reactive Sulfur Metabolome in Cells.

Hydrogen persulfide (H2S2) is an important sulfur-containing signaling molecule that plays a crucial role in the homeostasis of various organ systems, such as the renal, cardiovascular, liver, and gastrointestinal systems. However, research on H2S2 in biological settings is still challenging due to its instability and high reactivity. Compounds that can controllably release H2S2 (also known as donors) are thus crucial research tools. Currently, available H2S2 donors are still very limited, with most of them relying on modified disulfide templates. These templates possess an unavoidable limitation of being susceptible to cellular disulfide exchange which can compromise their efficacy. In this work, we explored nondisulfide-based and nonoxidation-dependent templates for the design of H2S2 donors. We found that tertiary naphthacyl thiols could undergo phototriggered C-S homolytic cleavage to form H2S2 via hydrosulfide (HS) radicals. In addition, the release of H2S2 was associated with the formation of a product with strong blue fluorescence, which allowed for real-time monitoring of the release process. This reaction was demonstrated to proceed effectively in both buffers and cells, with the ability to enhance intracellular production of persulfides, including GSSH, CysSSH, H2S2, H2S3, etc. It provides a unique photocontrolled H2S2 donor system with distinct advantages compared to known H2S2 donors due to its good stability and spatiotemporal control ability.

ESR spectroscopic analysis of fructose as a dosimeter for gamma radiation

In this research, fructose was used as a dosimeter, and ESR examined the influence of radiation dose on the dosimeter’s properties. Microwave power, g-value, and decay of response tests were carried out at doses of 1, 5, and 10 kGy. The results show that fructose possesses linearity at doses of 5 × 10−2–30 kGy. The radiation detection sensitivity of fructose is better than sucrose’s but less than alanine’s over the entire dose range. The irradiation dose influences microwave saturation on ESR intensity, occurring at 5 and 10 kGy. The microwave power for irradiated fructose ranges from 1.00 to 2.46 mW. The ESR signal intensity increases with higher radiation doses, primarily due to the formation of more free radicals. Additionally, higher radiation doses lead to faster decay of the fructose dosimeter’s response. The fructose ESR intensity stability compared to alanine and sucrose at 1, 5, and 10 kGy are alanine > sucrose > fructose, alanine > fructose > sucrose, and alanine > fructose ≈ sucrose, respectively.

Regulating Chlorine and Hydrogen Atom Transfer for Selective Photoelectrochemical C─C Coupling by Cu-coordination Effect at Semiconductor/Electrolyte Interfaces.

Semiconductor-based photoelectrochemical (PEC) organic transformations usually show radical characteristics, in which the reaction selectivity is often difficult to precisely control due to the nonselectivity of radicals. Accordingly, several simple organic reactions (e.g., oxidations of alcohols, aldehydes, and other small molecules) have been widely studied, while more complicated processes like C─C coupling remain challenging. Herein, a synergistic heterogeneous/homogeneous PEC strategy is developed to achieve a controllable radical-induced C─C coupling reaction mediated by the copper-coordination effect at the semiconductor/electrolyte interfaces, which additionally exerts a significant impact on the product regioselectivity. Through experimental studies and theoretical simulations, this study reveals that the copper-chloride complex effectively regulates the formation of chloride radicals, a typical hydrogen atom transfer agent, on semiconductor surfaces and stabilizes the heterogeneous interfaces by suppressing the radical-induced surface passivation. Taking the Minisci reaction (the coupling between 2-phenylquinoline and cyclohexane) as a model, the yield of the target C─C coupling product reaches up to 90% on TiO2 photoanodes with a selectivity of 95% and long-term stability over 100h. Moreover, such a strategy exhibits a broad scope and can be used for the functionalization of various heteroaromatic hydrocarbons.

Evaluation of the Effect of Gum Arabic on the Histological and Physiological Changes in the Liver of Albino Rats Exposed to Bisphenol A

We designed this work in order to study the protective effect of aqueous extract of gum arabic (GA) from oxidative damage induced by bisphenol A(BPA). This study was conducted on 35 male laboratory Albino rats of Sprague Dawley strain (165-210 grams) and divided into five groups. Each group included 7 rats. The experiment was performed at the animal house of Biology (College of Education for Pure Sciences). The experiment continued for 90 days under conditions Standard laboratory, as follows: The first group was the control; the second group had GA taken orally; the third group had BPA taken orally; the fourth group had GA taken first, followed by BPS, and the fifth group had BPA taken first, followed by GA. According to the above results clearly, Serum levels of AST, ALT and Lipid profile (Cholesterol, Triglyceride) indicated a highly significant increase in these parameters at group 3, While the fourth and fifth groups show significant reductions in AST, ALT, cholesterol, triglycerides, and MDA, also significant increases in GSH levels, While the histological changes in the third group were represented by the presence of a state of blood congestion with depletion of glycoprotein and degeneration of some cells, in addition to the presence of a state of necrosis of liver cells, while it was not observed severe histological changes when compared to third group in both fourth and fifth groups. In Short, the above results indicated that GA treatment for BPA-induced liver injury had Therapeutic effect through anti-free radical formation and functional role as free scavenger.

Hepatoprotective effect of silymarin-chitosan nanocomposite against aluminum-induced oxidative stress, inflammation, and apoptosis

Aluminum (Al) is abundant in the environment, and its toxicity is attributed to free radical formation and subsequent oxidative stress. While silymarin is a well-known antioxidant, its low water solubility and bioavailability limit its therapeutic effects. This study was designated to formulate silymarin chitosan nanoparticles (SM-CS-NPs) and evaluate its ameliorative effect against hepatotoxicity induced by aluminum chloride (AlCl3). SM-CS-NPs were prepared by ionotropic gelation method and characterized using different techniques. Rats were distributed into six groups (n=7/group), control, silymarin (SM; 15 mg/kg B.W), silymarin-chitosan nanoparticles (SM-CS-NPs; 15 mg/kg), aluminum chloride (AlCl3, 34 mg/kg), SM or SM-CS-NPs administrated orally one hour before the treatment with AlCl3 for 30 days, respectively. Results showed that supplementation of SM-CS-NPs or SM solo improved the antioxidant state and reduced oxidative stress. On the other hand, the pretreatment with SM-CS-NPs or SM followed by AlCl3 significantly restored liver functions (AST, ALT, ALP, LDH, total protein, albumin, globulin, and bilirubin) and modulated oxidative stress biomarkers (TBARS and H2O2), with improved cellular antioxidant defense (SOD, CAT, GPx, GR, GST, and GSH) and maintained normal liver histological structure compared to rats treated with AlCl3 alone. Furthermore, they alleviated the inflammation and apoptosis by downregulating the expression level of COX-2, caspase-3, and TNFα. This ameliorative effect was stronger with silymarin nanoform than in bulk-state silymarin. According to the findings, silymarin preparation in nanoform boosts its ameliorative and protective effects against AlCl3 hepatotoxicity.

Candida albicans pathways that protect against organic peroxides and lipid peroxidation.

Human fungal pathogens must survive diverse reactive oxygen species (ROS) produced by host immune cells that can oxidize a range of cellular molecules including proteins, lipids, and DNA. Formation of lipid radicals can be especially damaging, as it leads to a chain reaction of lipid peroxidation that causes widespread damage to the plasma membrane. Most previous studies on antioxidant pathways in fungal pathogens have been conducted with hydrogen peroxide, so the pathways used to combat organic peroxides and lipid peroxidation are not well understood. The most well-known peroxidase in Candida albicans, catalase, can only act on hydrogen peroxide. We therefore characterized a family of four glutathione peroxidases (GPxs) that were predicted to play an important role in reducing organic peroxides. One of the GPxs, Gpx3 is also known to activate the Cap1 transcription factor that plays the major role in inducing antioxidant genes in response to ROS. Surprisingly, we found that the only measurable role of the GPxs is activation of Cap1 and did not find a significant role for GPxs in the direct detoxification of peroxides. Furthermore, a CAP1 deletion mutant strain was highly sensitive to organic peroxides and oxidized lipids, indicating an important role for antioxidant genes upregulated by Cap1 in protecting cells from organic peroxides. We identified GLR1 (Glutathione reductase), a gene upregulated by Cap1, as important for protecting cells from oxidized lipids, implicating glutathione utilizing enzymes in the protection against lipid peroxidation. Furthermore, an RNA-sequencing study in C. albicans showed upregulation of a diverse set of antioxidant genes and protein damage pathways in response to organic peroxides. Overall, our results identify novel mechanisms by which C. albicans responds to oxidative stress resistance which open new avenues for understanding how fungal pathogens resist ROS in the host.

Optimizing the reaction pathway of methane photo-oxidation over single copper sites.

Direct photocatalytic conversion of methane to value-added C1 oxygenate with O2 is of great interest but presents a significant challenge in achieving highly selective product formation. Herein, a general strategy for the construction of copper single-atom catalysts with a well-defined coordination microenvironment is developed on the basis of metal-organic framework for selective photo-oxidation of CH4 to HCHO. We propose the directional activation of O2 on the mono-copper site breaks the original equilibrium and tilts the balance of radical formation almost completely toward •OOH. The synchronously generated •OOH and •CH3 radicals rapidly combine to form HCHO while inhibiting competing reactions, thus resulting in ultra-highly selective HCHO production (nearly 100%) with a time yield of 2.75 mmol gcat-1 h-1. This work highlights the potential of rationally designing reaction sites to manipulate reaction pathways and achieve selective CH4 photo-oxidation, and could guide the further design of high-performance single-atom catalysts to meet future demand.

Enantioselective Electrocatalysis for the Cross-Dehydrogenative Heteroarylation of Indoles, Pyrroles, and Furans.

Oxidative cross-dehydrogenative C-H/C-H functionalizations represent an exemplary approach for synthesizing carbonyl compounds via α-heteroarylation. Here we present the development of a direct anodic oxidative coupling process between 2-acylimidazoles and divergent heterocyclic systems including indole, pyrrole, and furan, facilitated by ferrocene-assisted asymmetric nickel electrocatalysis with high levels of enantioselectivity. Mechanistic investigations indicate that the reaction initially involves the formation of a chiral Ni-bound α-carbonyl radical, which is then captured by the heteroarene radical cation via intermolecular stereoselective radical/radical cation coupling. The mild, scalable, and robust reaction conditions allow for a broad substrate scope and excellent functional group tolerance, enabling access to a wide range of chiral hetero-compounds. The consequential α-heteroaromatic carbonyl products can potentially be transformed into a plethora of synthetically valuable frameworks, as exemplified by their application in the asymmetric total synthesis of (-)-COX-2 inhibitor, (+)-acremoauxin A, and (+)-pemedolac.

Binary and Ternary Deep Eutectic Solvents for Methylene Green Electropolymerization on Multiwalled Carbon Nanotubes: Optimization, Characterization and Application.

Choline chloride (ChCl) based binary and ternary deep eutectic solvents (DES) were evaluated for methylene green electropolymerization with oxalic acid (OA) and ethylene glycol (EG) as hydrogen bond donors. Binary DES ChCl : OA in molar ratios 1 : 1 and 2 : 1 and ChCl : EG 1 : 2 and ternary DES (tDES) in different molar ratios and percentages of water were evaluated. The highest polymer growth was in ChCl : OA : EG-tDES with 13% added water, that had a lower viscosity and higher ionic conductivity when associated with HCl as dopant. This enhanced the formation of more cation radicals and, consequently, more polymer formation. The PMG/MWCNT/GCE-tDES sensor was successfully applied to the simultaneous determination of 5-aminosalicylic acid (5-ASA) and acetaminophen (APAP) by differential pulse voltammetry in the concentration range 1 μM-200 μM, with detection limits of 0.37 μM and 0.49 μM for 5-ASA and APAP, respectively. The sensor demonstrated good repeatability, reproducibility and stability, and was successfully applied in pharmaceutical formulations.