Search Results (332)

Per- or polyfluoroalkyl substances (PFASs) are man-made compounds involved in compositions of many industrial processes and consumer products. The largest-volume man-made PFAS are made up of refrigerants and fluoropolymers. Major concerns for our society related to these substances are their contribution to global warming as greenhouse gasses and the potential for adverse effects on living organisms, particularly by long-chain perfluoroalkyl acid derivatives. Restrictions on manufacturing and applications will increase in the near future. The full remediation of historical and current contaminations of air, soil and water remains problematic, especially for ultra-short PFASs, such as trifluoroacetic acid. Future monitoring of PFAS levels and their impact on ecosystems remains important. PFASs have become integrated in the lifestyle and infrastructures of our modern worldwide society and are likely to be part of that society for years to come in essential applications by closing the fluorine loop. Full article

The difluoromethoxy (OCF₂H) and trifluoromethoxy (OCF₃) fluorinated structural motifs are frequently seen as privileged functional groups in the field of medicinal chemistry and are regularly taken into account during the design and development processes of successful drugs. This paper presents the synthesis of four new fluorinated etheric derivatives of cannabinol (CBN) using fluorine chemistry. These reactions are straightforward in terms of operation and make use of easily obtainable reagents, making them suitable for the synthesis of various fluorinated CBN ethers with yields ranging from moderate to excellent. We successfully isolated all the products and characterized them in detail using spectroscopic methods. It is anticipated that they will increase the efficacy of drug candidates due to their ability to alter biological activities such as cellular membrane permeability and metabolic stability and improve their pharmacokinetic properties. Full article

This study describes the synthesis of heterocyclic derivatives containing multiple nitrogen atoms serving as important moieties for developing novel antidiabetics through a simple synthetic pathway. We herein describe the synthesis and characterization of novel pyrimidine derivatives using one-pot reactions in a catalyst-free and efficient manner through a two-stage process involving the synthesis of 2-amino-4-hydrazinyl-6-methoxy pyrimidine, followed by a reaction with phenyl isothiocyanate derivatives. The structures of all the new compounds were confirmed via physical and spectral analysis. Furthermore, we evaluated the synthesized pyrimidine derivatives’ biological activities in relation to their potential roles as novel anti-diabetic agents by testing their activity profiles against the enzymes α-glucosidase and α-amylase. Compound 4 expressed the highest level of activity against α-glucosidase and α-amylase, with a greater inhibitory concentration (IC₅₀ of 12.16 ± 0.12 µM and IC₅₀ 11.13 ± 0.12 µM) compared to that of acarbose (IC₅₀ = 10.60 ± 0.17 µM and IC₅₀ = 11.30 ± 0.12 µM), which is widely used as a standard antidiabetic drug. The primary structure activity relationship analysis identified the impact of an electron- withdrawing group, especially with respect to fluorine on inhibitory activity. This was further confirmed in molecular docking studies, which demonstrated that both compounds exhibited similar inhibition patterns and emphasized the significance of incorporating a lipophilic electron-withdrawing substituent on the phenyl ring, along with the 2,4-diaminopyrimidine scaffold. Full article

We report the first syntheses—from commercially available 3-chloro-2-fluoroprop-1-ene (9)—of key garlic-derived compounds containing sp²-fluorine. We also report synthesis of fluoro-5,6-dihydrothiopyrans by trapping 2-fluorothioacrolein (15). Thus, difluoroallicin (12, S-(2-fluoro-2-propenyl) 2-fluoroprop-2-ene-1-sulfinothioate) is prepared by peracid oxidation of 1,2-bis(2-fluoro-2-propenyl)disulfane (11). S-2-Fluoro-2-propenyl-l-cysteine (2-fluorodeoxyalliin, 13), synthesized from cysteine and characterized by X-ray crystallography, is oxidized to its S-oxide, 2-fluoroalliin (22). The latter, with alliinase-containing powdered fresh garlic, gives a mixture of 12, allicin (1), and isomers of monofluoroallicin (23), indicating that 22 serves as a substrate for garlic alliinase. Upon heating, 12 generates transient 15, which dimerizes giving difluoro vinyl dithiins 6 and 7. Ethyl acrylate trapping of 15 affords 5- and 6-substituted 3-fluoro-5,6-dihydro-4H-thiopyrans (19 and 20). In 1,1,1,3,3,3-hexafluoro-2-propanol (HEFP) as solvent, 12 is converted into trifluoroajoene ((E,Z)-1-(2-fluoro-3-((2-fluoro-2-propenyl)sulfinyl)prop-1-en-1-yl)-2-(2-fluoro-2-propenyl)disulfane; 18). Liquid sulfur converts 11 to a (CH₂=CFCH₂)₂S_n mixture (n = 4–15), characterized by UPLC-(Ag⁺)-coordination ion spray-mass spectrometry. Full article

Silicon oxide–graphite is a promising high-capacity anode material for next-generation lithium-ion batteries (LIBs). However, despite using a small fraction (≤5%) of Si, it suffers from a short cycle life owing to intrinsic swelling and particle pulverization during cycling, making practical application challenging. High-nickel (Ni ≥ 80%) oxide cathodes for high-energy-density LIBs and their operation beyond 4.2 V have been pursued, which requires the anodic stability of the electrolyte. Herein, we report a nonflammable multi-functional fluorinated ester–based liquid electrolyte that stabilizes the interfaces and suppresses the swelling of highly loaded 5 wt% SiO–graphite anode and LiNi_0.88Co_0.08Mn_0.04O₂ cathode simultaneously in a 3.5 mAh cm⁻² full cell, and improves cycle life and battery safety. Surface characterization results reveal that the interfacial stabilization of both the anode and cathode by a robust and uniform solid electrolyte interphase (SEI) layer, enriched with fluorinated ester-derived inorganics, enables 80% capacity retention of the full cell after 250 cycles, even under aggressive conditions of 4.35 V, 1 C and 45 °C. This new electrolyte formulation presents a new opportunity to advance SiO-based high-energy density LIBs for their long operation and safety. Full article

Acute pneumonia is frequently accompanied by immune suppression, particularly affecting T-cell subsets, such as CD4⁺, CD4⁺CD25⁺, and CD4⁺CD25⁺FoxP3⁺, which are critical for immune regulation. This study evaluates the immunomodulatory potential of a novel fluorinated piperazine-based aminophosphonate, complexed with β-cyclodextrin ((o-Fph)PPhβCD), comparing it with the clinically approved agent Polyoxidonium (PO) in a rat model of oleic acid-induced acute pneumonia. Flow cytometric analysis revealed that (o-Fph)PPhβCD significantly restored CD4⁺ and CD4⁺CD25⁺ T-cell levels and induced a sustained reduction in regulatory CD4⁺CD25⁺FoxP3⁺ cells, suggesting enhanced effector immune activity. While PO provided early immunorestorative effects, (o-Fph)PPhβCD exerted a more prolonged response, which was particularly evident by day 14. Structural confirmation of the inclusion complex was achieved through IR and NMR spectroscopy. These findings highlight (o-Fph)PPhβCD as a promising immunotherapeutic candidate that is capable of rebalancing immune cell populations and supporting host defense mechanisms during acute pulmonary inflammation. Full article

We report on the preparation and characterization of a new family of hydrogen-bonded nematogenic liquid crystalline dimers. The dimers are supramolecular complexes that consist of a benzoic acid derivative, acting as the proton donor, featuring a spacer with seven methylene groups and a terminal decyloxy chain, paired with an azopyridine derivative as the proton acceptor. The latter was either fluorinated or nonfluorinated with variable alkoxy chain length. The formation of a hydrogen bond between the individual components was confirmed using FTIR and ¹H NMR spectroscopy. All supramolecules were investigated for their liquid crystalline behaviour via a polarized optical microscope (POM) and differential scanning calorimetry (DSC). All materials exhibit enantiotropic nematic phases as confirmed by X-ray diffraction (XRD) and POM investigations. The nematic phase range depends strongly on the degree and position of fluorine atoms. Additionally, the supramolecules demonstrated a rapid and reversible transition between the liquid crystal phase and the isotropic liquid state because of trans-cis photoisomerization upon light irradiation. Therefore, this study presents a straightforward approach to design photo-responsive nematic materials, which could be of interest for nonlinear optics applications. Full article

The inherent flammability and hydrophilicity of nylon/cotton (NC) blend fabrics limit their practical applications. Traditional hydrophobic treatments often involve fluorinated compounds or nanomaterials, which raise environmental concerns and exhibit poor durability. To address these issues, this study developed a sustainable multifunctional finishing strategy. Initially, the nylon/cotton blended fabric was pretreated with 3-glycidyloxypropyltrimethoxy silane (GPTMS). An intumescent flame retardant coating based on bio-derived phytic acid (PA) and polyethyleneimine (PEI) was constructed on NC fabrics via a layer-by-layer (LBL) self-assembly process. Subsequently, polydimethylsiloxane (PDMS) was grafted to reduce surface energy, imparting synergistic flame retardancy and superhydrophobicity. The treated fabric (C-3) showed excellent flame retardant and self-extinguishing behavior, with no afterflame or afterglow during vertical burning and a char length of only 35 mm. Thermogravimetric analysis revealed a residual char rate of 43.9%, far exceeding that of untreated fabric (8.6%). After PDMS modification, the fabric reached a water contact angle of 157.8°, indicating superior superhydrophobic and self-cleaning properties. Durability tests showed that the fabric maintained its flame retardancy (no afterflame or afterglow) and superhydrophobicity (WCA > 150°) after 360 cm of abrasion and five laundering cycles. This fluorine-free, nanoparticle-free, and environmentally friendly approach offers a promising route for developing multifunctional NC fabrics for applications in firefighting clothing and self-cleaning textiles. Full article

Flavonoids and chalcones, widely recognised for their diverse biological activities, have garnered attention due to their potential therapeutic applications. This review discusses fluorinated flavonoids and chalcones, focusing on their prospective anti-inflammatory, antidiabetic, anticancer, antiosteoporotic, cardioprotective, neuroprotective, hepatoprotective, antimicrobial, and antiparasitic applications. The enhanced biological activities of fluorinated derivatives, particularly the antibacterial, antiviral, and anticancer properties, are attributed to the introduction of fluorine groups, which increase lipophilicity and metabolic stability. Key findings indicate that fluorinated flavonoids and chalcones exhibit synergistic effects with antibiotics, inhibit bacterial efflux pumps, and reveal potent antiviral and anticancer properties. However, challenges such as cytotoxicity and structural optimisation have to be addressed. The synthesis of fluorinated flavonoids and chalcones is discussed, with emphasis on various synthetic methods such as condensation and cyclisation reactions starting from fluorinated precursors, as well as fluorination strategies, including the use of molecular fluorine or fluorinating agents. Fluorinated flavonoids and chalcones represent candidates for therapeutic development and have the potential to overcome drug resistance. However, further studies are necessary to adjust their pharmacological profiles. Full article

This perspective highlights current trends and recent advances in the introduction of fluorine and fluoroalkyl moieties into the furanic core of biobased furfural-derived furans. Existing and potential applications of these fluorinated building blocks in the development of pharmaceuticals and advanced materials are also discussed. Full article

Carbon nanofibrous materials from electrospinning are good candidate electrode materials for supercapacitor applications due to their straightforward processability, chemical stability, high porosity, and large surface area. In this research, a straightforward and effective way was revealed to significantly enhance the electrochemical performance of carbon nanofibrous electrode material from electrospinning of polyacrylonitrile (PAN). Fluorination of the electrospun carbon nanofibers (ECNF) was studied by comparing two types of hydrofluoric acid (HF) treatment, i.e., direct HF acid treatment on ECNF (Type I) vs. HF acid treatment on the stabilized PAN (Type II) followed by carbonization. The latter was found to be an advantageous way to introduce C-F bonds in the resultant carbon nanofibrous electrode material that contributed to pseudocapacitance. Furthermore, the Type II HF acid treatment demonstrated exciting synergistic effects with ECNF aerogel formation on carbon structure and porosity development and generated a superior fluorinated electrospun carbon nanofibrous aerogel (ECNA-F) electrode material for supercapacitor uses. The resultant ECNA-F electrode material demonstrated excellent electrochemical performance with great cyclic stability due to the large improvements in both pseudocapacitance and electrical double-layer capacitance. ECNA-F achieved a specific capacitance of 372 F/g at a current density of 0.5 A/g with 1 M H₂SO₄ electrolyte, and the device with ECNA-F and 1 M Na₂SO₄ electrolyte possessed an energy density of 29.1 Wh/kg at a power density of 275 W/kg. This study provided insight into developing high-performance and stable carbon nanofibrous electrode materials for supercapacitors. Full article

The aluminum electrolysis industry faces significant challenges due to the high consumption and environmental impact of carbon anodes, which are prone to oxidation in high-temperature and strongly oxidizing environments. This study innovatively introduces aluminum fluoride (AlF₃) as an additive to enhance the oxidation resistance of carbon anodes for aluminum electrolysis. By systematically exploring microstructural evolution through SEM, XRD, Raman spectroscopy, and permeability analyses, it reveals that AlF₃ inserts fluorine atoms into carbon interlayers, forming F-C bonds that reduce interlayer spacing while promoting graphitization. Simultaneously, AlF₃-derived α-Al₂O₃ particles densify the anode and make it more compact, reaching the optimum when 7 wt.% AlF₃ is doped. The bulk density of the carbon anode increased to 2.08 g/cm³, porosity decreased to 0.315, and air permeability reached a minimum of 2.3 nPm. In addition, the fluorine intercalation reduces the electrical resistance to 2.12 Ω via conductive F-C clusters. The demonstrated efficacy of AlF₃ additives in enhancing the oxidation resistance and conductivity of carbon anodes suggests strong potential for industrial adoption, particularly in optimizing anode composition to reduce energy consumption. Full article

LiFePO₄ (LFP) batteries are among the earliest commercialized and most discarded lithium-ion batteries. Although existing recovery technologies focus on the conversion of LiFePO₄ to Li₂CO₃, challenges associated with achieving near-full recovery and high-value products remain. This study proposes a strategy for the conversion of spent LiFePO₄ to LiF by mechanical chlorination coupled with a fluorination reaction. The optimum conditions were determined to be a ball-to-powder ratio (BPR) = 15, NH₄Cl:LFP = 3, H₂O₂ = 2.0 mL, rotation speed = 600 rpm, and grinding time = 12 h. Results showed that 97.14% Li was converted into LiCl by H₂O₂–NH₄Cl mechanical chlorination. When chlorinated intermediates were immersed in water, FePO₄ could be harvested, and 96.79% Li could be recovered as LiF with a purity of 99.50% after adding NH₄F. When Cl-functionalized renewable resin was used to exchange 99.89% F⁻, 0.63 g NH₄Cl per litre of LiF conversion residual liquid was derived. The favourable results were attributed to the ¹O₂ generated by H₂O₂, which had a strong electron affinity to break Li–O bonds and provided superior conditions for the combination of Li and Cl. During fluorination, the formation of LiF reduced the ion concentration, and the entropy decreased, contributing to the spontaneous reaction. Therefore, the proposed method paves the way for near-full recovery and high-value products of spent LiFePO₄. Full article

In view of sustainable-by-design issues, there is an urgent need for replacing harmful coating ingredients with more ecological, non-toxic alternatives from bio-based sources. In particular, fluorine derivatives such as polytetrafluoroethylene (PTFE) powders are frequently applied as coating additives because of their versatile role in rendering hydrophobicity and lubrication. In this research, a screening study is presented regarding the performance of alternative micronized biowax powders, produced from various natural origins, when used as functional additives in protective epoxy coatings for wood. The micronized wax powders from bio-based sources (carnauba wax, rice bran wax, amide biowax) and reference fossil sources (PE wax/PTFE, PE wax, PTFE), of large (8 to 11 µm) and small sizes (4 to 6 µm), were added into fully bio-based epoxy clear coat formulations based on epoxidized flaxseed oil and proprietary acid hardener. Within concentration ranges of 0.5 to 10 wt.-%, it was observed that rice bran micropowders present higher hardness, scratch resistance, abrasion resistance, and hydrophobicity when compared to the results for PTFE. Moreover, the proprietary mixtures of biowax combined with PTFE micropowders provide synergistic effects, with PTFE mostly dominating in regards to the mechanical and physical properties. However, the granulometry of the micronized wax powders is a crucial parameter, as the smallest biowax particle sizes are the most effective. Based on further analysis of the sliding interface, a more ductile surface film forms for the coatings with rice bran and carnauba wax micropowders, while the amide wax is more brittle in parallel with the synthetic waxes and PTFE. Infrared spectroscopy confirms a favorable distribution of biowax micropowders at the coating surface in parallel with the formation of a protective surface film and protection of the epoxy matrix after abrasive wear. This study confirms that alternatives to PTFE for the mechanical protection, gloss, and hydrophobicity of wood coatings should be critically selected among the available grades of micronized waxes, depending on the targeted properties. Full article

Perfluoropropionic acid (CF₃CF₂C(O)OH) has been investigated with a focus on its complex structural properties. As a formal derivative of propanoic acid, the incorporation of fluorine atoms imparts unique structural features, including three distinct monomeric conformations and a dimeric structure. This study presents experimental findings, supported by computational modeling, to explore these characteristics. The analysis includes an FTIR study of the isolated species in an Ar-cryogenic matrix and the low-temperature determination of its crystalline structure using single-crystal X-ray diffraction. Full article