Carbonyl Function Research Articles

Surface functionalization of ethylene–tetrafluoroethylene copolymer film with poly(methyl methacrylate) via chemical radical polymerization

The surface of a poly(ethylene-co-tetrafluoroethylene) (ETFE) film was modified by grafting of methyl methacrylate (MMA) by using diethyl(1,10-phenanthroline N1,N10)zinc (Phen-DEZ) and oxygen molecules as the radical initiator. Fourier transform infrared (FT-IR) spectra and Raman spectra of polymethylmethacrylate-grafted-ETFE (ETFE-g-PMMA), showed absorption peaks attributed to carbonyl functionalities. And the thermal decomposition of ETFE-g-PMMA was observed in two stages. The first weight loss step was due to the disruption of the grafted PMMA polymer, while the second degradation step was likely due to thermal disruption of ETFE itself. These results provide clear evidence of PMMA grafting onto ETFE film. The grafting yield of MMA was found to be affected by the polymerization temperature, reaction time, and concentration of Phen-DEZ. Analysis of the surface morphology of the film by atomic force microscopy (AFM) suggests that MMA was grafted on the surface of the ETFE film. In addition, the water contact angle on the hydrophobic surface of the ETFE film changed from 94.6° to 65.5° depending on the graft of PMMA, resulting in hydrophilicity. Moreover, the results of the dyeing experiment showed that only the surface of the ETFE film was decorated with MMA and the interior was unchanged.

Ultrasound promoted synthesis of N-(substituted phenyl)-2-(7‑hydroxy-4-methyl-2H-chromen-2-ylidene)hydrazine-1-carboxamides as cytotoxic and antioxidant agents

New N-(substituted phenyl)-2-(7‑hydroxy-4-methyl-2H-chromen-2-ylidene)hydrazine-1-carboxamides (5a-l) was synthesized in two steps using environmentally friendly ultrasound irradiation. The first step involved solvent free synthesis of 7‑hydroxy-4-methyl-2H-chromen-2-one (3) by using catalytic amount (10% mol) of FeCl3. The second step involved condensation of intermediate 3 and hydrazine carboxamide HCl analogues (4a-l) under ultrasonic influence in the water-ethanol (2:1) solvent system to obtain the title compounds (5a-l) in good yield. The structure of prepared compounds (5a-l) was confirmed by spectroscopic study. The synthetic strategy described here has many advantages, including a simple procedure and high conversion with quick reaction times. The cytotoxicity was tested on 60 NCI cancer cell lines at 10 µM and N-(4-chlorophenyl)-2-(7‑hydroxy-4-methyl-2H-chromen-2-ylidene)hydrazine-1-carboxamide (5b) showed promising activity with maximum sensitivity against CCRF-CEM, UO-31, RPMI-8226, NCI-H522, and HL-60(TB) with growth percent (GP) of 17.50, 79.67, 80.59, 82.35, and 83.70 respectively. In a DPPH free radical scavenging assay, the compounds 5b and 5d showed promising antioxidant activity with IC50 values of 16.32±1.29 and 14.28±1.82 M, respectively. The binding affinity of the target ligands (5a-l) against the active site of FGFR was also investigated using molecular docking. Within the active site of FGFR4, the ligand 5b interacted with four H-bonds with Asp630 (carbonyl function), Glu520 (with amide NH and ArNH), and Ile609 (phenol function), while an imine “N” showed two salt bridges with Asp630 and Glu520.

Tailoring Impact of Carbonyl Functionalities on Electrochemical Redox Properties of Anthraquinone

A fundamental understanding of the effect of incorporating diverse carbonyl functionalities into well-known redox-active compounds, such as anthraquinone, is essential to develop organic cathode ma...

Pyrolysis of flaxseed residue: Exploration of characteristics of the biochar and bio-oil products

In this study, the pyrolysis of flaxseed residue (FSR), a solid waste in the production of flaxseed oil, was carried out, aiming to understand the characteristics of the pyrolysis products. Comparing with traditional biomass (such as poplar wood), the organic components in FSR are easier to be cracked, producing the bio-oil with little heavy components. The high content of proteins in FSR made the resulting bio-oil nitrogen-rich. The resulting biochar contained abundant nitrogen, as some of the N-containing organics were thermally stable even at 650 °C. The significant cracking reactions made the biochar with the relatively lower carbon content, heating value and energy yield than that from biomass. The changes of functionalities of the biochar versus increasing temperature were also characterized with in situ diffuse reflectance infrared fourier transforms spectroscopy technique. The transformation of the carbonyl and other functionalities on surface of the biochar was sensitive to the change of temperature and the increase of temperature promoted the deoxygenation and aromatization reactions.

Photolysis of multifunctional carbonyl compounds under natural irradiation at EUPHORE

Photolysis is one the main drivers in atmospheric chemistry. Volatile organic compounds that bear one or more carbonyl functions can absorb UV light between 295 nm and 450 nm, enabling them to possibly photolyze in the atmosphere. Yet, very few data are available regarding the impact of such photolysis processes on the fate of multifunctional carbonyls. In the present work, we investigated the photodissociation of one α-diketone and three hydroxyketones under real sunlight at the European Photoreactor EUPHORE. The obtained photolysis frequencies normalized by NO2 photolysis were: 2,3-pentanedione (PTD): (3.4 ± 0.6) × 10−2, 4-hydroxy-4-methyl-2-pentanone (4H4M2P): (6.2 ± 2.9) × 10−4, 3-hydroxy-3-methyl-2-butanone (3H3M2B): (8.2 ± 4.9) × 10−4, and 4-hydroxy-3-hexanone (4H3H): (5.1 ± 3.0) × 10−4. These ratios represent the first data for three of them, to our knowledge. Reaction products were also investigated and carbon balances of 70–100% in the gas-phase have been obtained. A photolysis reaction mechanism is proposed for 4H3H for the first time, based on the observed products. Atmospheric lifetimes span between 39 min for PTD to 1–2 days for hydroxyketones. The present work shows that photolysis of multi-oxygenated VOCs may be significant and needs to be taken into account in atmospheric chemistry models where it represents an additional source of radicals.

Antibacterial and Catalytic Performance of Green Synthesized Silver Nanoparticles Embedded in Crosslinked PVA Sheet

In this research work, a green method of using Saussurea costus extract for the synthesis of silver nanoparticles (AgNPs) is developed. Analysis of the synthesized AgNPs showed that the hydroxyl and carbonyl functionalities of the Saussurea costus extract are playing major roles in their synthesis. X-ray diffraction revealed that the AgNP has face-centered cubic crystal structure. Field emission scanning electron microscopy suggested that the AgNP nanoparticles has a spherical shape with sizes ranging ~ 45 ± 15 nm. Furthermore, these green synthesized AgNPs were applied in the catalysis as well as biomedical fields. AgNPs were embedded in a crosslinked thin polyvinyl alcohol sheet and repeatedly used in the 4-nitrophenol (4-NP) reduction for 8 times. A high activity was observed for the Saussurea costus extract synthesized AgNP (S.C./AgNP) where the rate constant was 0.441 min− 1. The antibacterial studies on Escherichia coli, and Acinetobacter baumannii (gram negative) and Staphylococcus aureus and Methicillin-resistant Staphylococcus aureus (MRSA) (gram positive) bacterial strains showed a good potential of the S.C./AgNP in killing these pathogens at a concentration of 1 µg/ml.

Break‐and‐Build Strategy for the Synthesis of 2‐Benzoylbenzoxazoles from o‐Aminophenols and Acetophenones

AbstractAlthough compounds with a 2‐benzoylbenzoxazole motif are biologically relevant, there are only a few methods for synthesizing them, most of which relied on multistep process or required substrates bearing activating groups. Herein, we report an efficient method for the synthesis of such compounds by direct reactions of o‐aminophenols with acetophenones promoted by sulfur in DMSO. The reaction was found to proceed via a Willgerodt rearrangement‐type benzoxazolation of acetophenones followed by a benzylic oxidation to reinstall the carbonyl function. This method has a broad substrate scope and good tolerance for sensitive functional groups.magnified image

Steam reforming of sugars: Roles of hydroxyl group and carbonyl group in coke formation

Steam reforming of sugars features with the high tendency towards coke formation, which relates to the multiple hydroxyl groups and the carbonyl functionality. In this study, steam reforming of glucose, fructose and sorbitol were conducted to clarify the roles of these functionalities in the formation of coke. The results showed that reforming of sorbitol produced more hydrogen and less coke, unlike those of glucose and fructose which produced rather little hydrogen and too much coke. The carbonyl functionality was the main reason for the serious coking behavior but not the multiple hydroxyl groups. The coke from the reaction of sorbitol was mainly catalytic coke with a higher C/H and more defective large fused aromatic rings, which was more thermally stable, more resistant towards oxidation and having a higher crystallinity. Unlike those produced by the reforming of glucose and fructose. Functionalities of the sugars determined the properties of the coke generated.

Distinct Tetracyanoquinodimethane Derivatives: Enhanced Fluorescence in Solutions and Unprecedented Cation Recognition in the Solid State.

Tetracyanoquinodimethane (TCNQ) is known to react with various amines to generate substituted TCNQ derivatives with remarkable optical and nonlinear optical characteristics. The choice of amine plays a crucial role in the outcome of molecular material attributes. Especially, mono/di-substituted TCNQ’s possessing strong fluorescence in solutions than solids are deficient. Furthermore, cation recognition in the solid-state TCNQ derivatives is yet undetermined. In this article, we present solution-enhanced fluorescence and exclusive solid-state recognition of K+ ion achieved through the selection of 4-(4-aminophenyl)morpholin-3-one (APM) having considerable π-conjugation and carbonyl (C=O) functionality, particularly in the ring. TCNQ when reacted with APM, in a single-step reaction, resulted in two well-defined distinct compounds, namely, 7,7-bis(4-(4-aminophenyl)morpholin-3-ono)dicyanoquinodimethane (BAPMDQ [1], yellow) and 7,7,8-(4-(4-aminophenyl)morpholin-3-ono)tricyanoquinodimethane (APMTQ [2], red), with increased fluorescence intensity in solutions than their solids. Crystal structure investigation revealed extensive C–H−π interactions and strong H-bonding in [1], whereas moderate to weak interactions in [2]. Surprisingly, simple mechanical grinding during KBr pellet preparation with [1, 2] triggered unidentified cation recognition with a profound color change (in ∼1 min) detected by the naked eye, accompanied by a drastic enhancement of fluorescence, proposed due to the presence of carbonyl functionality, noncovalent intermolecular interactions, and molecular assemblies in [1, 2] solids. Cation recognition was also noted with various other salts as well (KCl, KI, KSCN, NH4Cl, NH4Br, etc.). Currently, the recognition mechanism of K+ ion in [1, 2] is demonstrated by the strong electrostatic interaction of K+ ion with CO and simultaneously cation−π interaction of K+ with the phenyl ring of APM, supported by experimental and computational studies. Computational analysis also revealed that a strong cation−π interaction occurred between the K+ ion and the phenyl ring (APM) in [2] than in [1] (ΔGbinding calculated as ∼16.3 and ∼25.2 kcal mol–1 for [1] and [2], respectively) providing additional binding free energy. Thus, both electrostatic and cation−π interactions lead to the recognition. Scanning electron microscopy of drop-cast films showed microcrystalline “roses” in [1] and micro/nano “aggregates” in [2]. Optical band gap (∼3.565 eV) indicated [1, 2] as wide-band-gap materials. The current study demonstrates fascinating novel products obtained by single-pot reaction, resulting in contrasting optical properties in solutions and experiencing cation recognition capability exclusively in the solid state.

A DFT mechanistic study on oxidative dehydrogenative Diels–Alder reaction of alkylbenzenes

Cross-dehydrogenative Diels-Alder cycloaddition reaction between readily-available alkyl benzenes and electron-deficient dienophiles is an attractive synthetic route to access carbocyclic compounds which have high utility in the chemical and pharmaceutical industries. This work reports a study at the M06-2X/6-311G(d) and M06-2X/6–311++G(d,p) levels of theory on the reaction of alkyl benzenes with electron-deficient dienophiles in the presence of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) as an oxidant and hydroquinone as an activator, so as to understand the chemoselectivity of the reaction (addition across the alkene functionality versus the ketone functionality), the role of the activator, the effects of substituents and the effect of solvent on the reaction. The results show the addition of the alkene bonds of methylstyrene across the alkene functionality of the electron-deficient dienophiles has generally low barriers compared to the addition across the carbonyl functionality of the electron-deficient dienophile. Powerful electron-withdrawing group (cyano) on the electron-deficient dienophile decrease the energy barrier for the cycloaddition and decrease the stability of the product whiles weak electron-withdrawing (bromine and chlorine) and electron-donating groups increase the energy barrier for the cycloaddition and decrease the stability of the product. The hydroquinone as an activator decreases the activation barrier for the Diels-Alder cycloaddition reaction.

Impacts of residence time on transformation of reaction intermediates and coking behaviors of acetic acid during steam reforming

Liquid hourly space velocity (LHSV) is a critical factor in steam reforming as it not only determines process capacity of reformer, but also affect the properties of the coke formed via impacting the activation of the reactants and the formation of the products. In this study, the impacts of LHSV on the properties of the coke formed in steam reforming of acetic acid over Ni/SBA-15 catalyst were investigated. The results indicated that the increasing LHSV promoted the formation of the gaseous by-products and accelerated coking, as the low residence time was not conducive for activation of steam. The coke formed at the higher LHSV was more aromatic and have more fused but defective ring structures. Furthermore, at the low steam ratio in reactants, the high LHSV could also promoted the retainment of the carbonyl functionality in the coke. These phenomena are mainly due to the higher abundance of the organic species on surface of the catalyst under the high LHSV. In addition, not only the cavity of the carbon nanotube but also other morphologies the coke such as carbon nanofiber, bamboo-like structure and string beads-like structure was closely related to the LHSV, as LHSV impacted the reaction intermediates formed and further on the precursors of the coke.

A practicable synthesis of 2,3-disubstituted 1,4-dioxanes bearing a carbonyl functionality from α,β-unsaturated ketones using the Williamson strategy

We have observed that a reagent combination of NaIO4 and NH2OH·HCl reacts with α,β-unsaturated ketones followed by the nucleophile ethylene glycol allowing the synthesis of 2,3-disubstituted 1,4-dioxanes using cesium carbonate as a base under Williamson ether synthesis. This reaction is useful for the synthesis of functionalized 1,4-dioxane having a carbonyl functionality. A variety of 2,3-disubstituted 1,4-dioxanes have been synthesized using these reaction conditions. A probable reaction mechanism has also been proposed.

Graphitic bio-char and bio-oil synthesis via hydrothermal carbonization-co-liquefaction of microalgae biomass (oiled/de-oiled) and multiple heavy metals remediations

Thermochemical transformation of microalgae biomass into graphitic bio-chars entices as proficient bio-adsorbents for heavy metal contaminants. This study explores the synergistic impact of Chlorella sorokiniana on biomass generation and wastewater remediation in high rate algae pond (HRAP). Biomass produced was applied for hydrothermal carbonization-co-liquefaction (HTCL). The structural and morphological characteristics of HTCL products (i.e. bio-chars and bio-oils) have been systematically studied by XRD, Raman, FTIR, elemental analyzer, SEM, BET, and 1H NMR spectroscopy. The crystallite size of the graphite 2H indexing planes was to be 4.65 nm and 14.07 nm in the bio-chars of oiled biomass (MB-OB) and de-oiled biomass (MB-DOB), respectively. The increase in the ID/IG ratio of MB-DOB indicated the highly disordered graphitic structure due to the appearance of carbonyl, hydroxyl, and epoxy functionalities in the line of high C/N and low C/H ratio. Also, the multiple heavy metals remediation of MB-DOB revealed better efficiency as ~100% in 720 min. The kinetics analysis shows the correlation coefficient of pseudo-second-order is well fitted compared to the pseudo-first-order. The Langmuir adsorption model signifies the adsorption of heavy metal ions in a monolayer adsorption manner. The study proposes the microalgae bio-char potential for multiple heavy metals remediation alongside bio-oils.

Construction of Bridged Polycyclic Skeletons via Transition-Metal Catalyzed Carbon-Carbon Bond-Forming Reactions.

Transition-metal catalysis has become one of most important methods for constructing molecules with diverse architectures. Bridged polycyclic skeletons are often considered one of most challenging structures in organic synthesis. This Minireview summarizes the recent progress on synthesis of bridged polycyclic skeletons by transition-metal-catalyzed carbon-carbon bond-forming reaction. Four main ring-forming strategies including connection via olefin or carbonyl functionality, enolate intermediacy, C-H functionality, and aryl functionality are detailed and some effective methods are discussed with particular emphasis on reaction design and mechanism.

Tailored oxidation of hydroxypropyl cellulose under mild conditions for the generation of wet strength agents for paper

Secondary hydroxyl groups of hydroxypropyl cellulose (HPC) are transformed into reactive carbonyl groups selectively via TEMPO-mediated oxidation in the presence of sodium hypochlorite. By using this oxidation protocol, we introduced carbonyl functions in HPC under mild conditions, with a controlled degree of oxidation (DOx) up to 2.5 and a low degradation of the polysaccharide. The effect of the concentration of sodium hypochlorite on the resulting oxidized alcohol groups has been investigated in detail. Oxidized HPC crosslinks spontaneous at room temperature and mild pH-values with a variety of amines to form water stable hydrogels. If applied on lab-made paper sheet, thermally cross-linking this polymer with amines significantly increased the wet tensile strength. The utilization of such wet strength agents could lead to new approaches in terms of recyclability and biodegradability of wet strength agents interesting for a large number of different paper grades.

Functionalized Trigonal Lanthanide Complexes: A New Family of 4f Single-Ion Magnets.

We report the synthesis, characterization, and magnetic properties of eight neutral functionalized trigonal lanthanide coordination complexes LnL with Ln = Gd (1), Tb (2), Dy (3), Ho (4), Er (5), Tm (6), Yb (7), Lu (8). These were prepared through a one-pot synthesis where, first, the ligand H3L was synthesized in situ through a Schiff base reaction of tris(2-aminoethyl)amine with 2,6-diformyl-p-cresol. Following addition of Ln(OTf)3·xH2O and base, LnL was obtained. Powder X-ray diffraction confirms that all complexes are isostructural. LnL contain pendant, noncoordinating carbonyl functions that are reactive and represent direct anchoring points to appropriately functionalized surfaces. Furthermore, these reactive carbonyl functions can be used to postfunctionalize LnL: for example, with aromatic π systems. We present herein the Schiff base condensation of 7 with benzylamine to yield 9 as well as the characterization and magnetic properties of 9. Our study establishes LnL as a truly versatile module for the surface deposition of Ln-based single-ion magnets.

The explosive trinitrotoluene (TNT) induces gene expression of carbonyl reductase in the blue mussel (Mytilus spp.): a new promising biomarker for sea dumped war relicts?

Millions of tons of all kind of munitions, including mines, bombs and torpedoes have been dumped after World War II in the marine environment and do now pose a new threat to the seas worldwide. Beside the acute risk of unwanted detonation, there is a chronic risk of contamination, because the metal vessels corrode and the toxic and carcinogenic explosives (trinitrotoluene (TNT) and metabolites) leak into the environment. While the mechanism of toxicity and carcinogenicity of TNT and its derivatives occurs through its capability of inducing oxidative stress in the target biota, we had the idea if TNT can induce the gene expression of carbonyl reductase in blue mussels. Carbonyl reductases are members of the short-chain dehydrogenase/reductase (SDR) superfamily. They metabolize xenobiotics bearing carbonyl functions, but also endogenous signal molecules such as steroid hormones, prostaglandins, biogenic amines, as well as sugar and lipid peroxidation derived reactive carbonyls, the latter providing a defence mechanism against oxidative stress and reactive oxygen species (ROS). Here, we identified and cloned the gene coding for carbonyl reductase from the blue mussel Mytilus spp. by a bioinformatics approach. In both laboratory and field studies, we could show that TNT induces a strong and concentration-dependent induction of gene expression of carbonyl reductase in the blue mussel. Carbonyl reductase may thus serve as a biomarker for TNT exposure on a molecular level which is useful to detect TNT contaminations in the environment and to perform a risk assessment both for the ecosphere and the human seafood consumer.

The reactivity of tetrahydropyrrolo[1,2-b]isothiazol-3(2H)-one 1,1-dioxides

The present work is devoted to the study of the reactivity of tetrahydropyrrolo[1,2-b]isothiazol-3(2H)-one 1,1-dioxide framework. This scaffold possesses two reaction centers: the EWG-activated methylene group and the carbonyl functionality, which are the basic variation points. At the same time, the attached 3a-substituent had a significant impact on the course of the explored reactions and its role was also investigated. In this regard, the corresponding 3a-unsubstituted and 3a-methylated tetrahydropyrrolo[1,2-b]isothiazol-3(2H)-one 1,1-dioxides were chosen as model substances involved in chemical properties evaluation. With a view to pre-assess the activity of the model compounds, a deuteration study was conducted. Furthermore, the interaction with a variety of electrophilic and nucleophilic agents was explored. The most striking difference in the chemical behavior was observed in the reaction with the Wittig reagent triphenylcarbethoxymethylenephosphorane (Ph3P=CHCO2Me). In particular, unlike the 3a-unsubstituted substrate, the 3a-methylated one gave the unusual phosphonium betaine, namely 3a-methyl-2-[2-(triphenylphosphonio)acetyl]-3a,4,5,6-tetrahydropyrrolo[1,2-b]isothiazol-3-olate 1,1-dioxide. The proposed mechanistic insights of this reaction have been discovered.

Inter- and Intramolecular [2+2+2] Cycloaddition of Alkyne Triple Bonds to the Carbonyl Function of Aldehydes and Ketones Enabled by η5-Cyclopentadienylcobalt(L)(L′)

Abstract1,7-Octadiyne underwent [2+2+2] cycloaddition to acetone in the presence of η5-cyclopentadienylcobalt(L)(L′) complexes to give (η5-cyclopentadienyl)[(1,4,4a,8a-η4)-5,6,7,8-tetrahydro-3,3-dimethyl-3H-2-benzopyran]cobalt, in which the two triple bonds and the carbonyl moiety have combined to engender a 2H-pyran ring complexed to CpCo. The scope of this reaction was explored, including cocyclizations of ynals and ynones with bis(trimethylsilyl)acetylene, as well as all-intramolecular reorganizations of α,ω-diynals and -diynones. Two major trajectories were observed in the case of aldehydes, the (often minor) [2+2+2] pathway and a competing trail featuring a formal 1,5-hydride shift that results in CpCo–dienones. The latter is obviated for ketone substrates. Preliminary chemistry of selected complexes uncovered unprecedented reactions, such as acid-catalyzed ring openings and additions of amines, the latter providing access to novel carbon frames.

Electrolyte formulation to enable ultra-stable aqueous Zn-organic batteries

Aqueous zinc batteries (ZBs) possess great potential in energy storage due to their advantages in safety, low-cost and resource abundance. However, the commercialization of ZBs is plagued by the lacking of suitable cathode structures (or nano-textures) and their poor cycle life. The popular cathode materials of Mn or V based oxides suffer from the high solubility and toxicity of transition metals (TMs). It is highly required to develop robust TM-free organic cathodes with design flexibility and environmental benignity. Herein, 1,4,5,8-naphthalene diimide (NDI) layered molecules are proposed as cathode candidate for ZBs, and they are characterized by sufficient interconnection of nano-particles (for continuous electron transport) into porous network (for facilitated ion filtration). It enables the achievement of reversible redox of carbonyl function groups and a stable gravimetric capacity around 200 mAh g−1. The superior cycling and rate performance (at least 5000 cycles under 3 A g−1) benefits from the electrolyte formulation. The blending of Na2SO4 additive takes effect in terms of the cathode grain attenuation into ultrathin 2D nanosheets, pseudo-capacitance contribution enhancement and Zn anode smoothening.