Fluorine Containing Research Articles

Ion Conduction Mechanism and Interfacial Stability in Fluorine Containing Lithium Argyrodite Electrolytes for Solid-State Lithium-Sulfur Batteries

Solid-state lithium-sulfur batteries (SSLSBs) hold great potential as a safe and energy-dense storage technology for wide variety of applications. Among solid-state electrolytes, halogen-doped lithium argyrodites have become an attractive category. This is attributed to their notable features, including high lithium-ion conductivity (~10-3 S/cm), favorable elastic stiffness (~ 30 GPa), and low flammability, making them promising candidates for enhancing the performance of SSLSBs.Despite their potential, SSLSBs based on sulfide faces challenges due to a limited atomic-scale understanding of ion-conduction, charge transport, structural evolution, and interfacial reactions such as dendrite growth, electrolyte decomposition. Here we employ a combination of density functional theory calculations, and ab initio molecular dynamics simulations to address this challenge for fluorinated argyrodites. Specifically, using accurate materials modeling, we design fluorine-containing argyrodite electrolytes that simultaneously offer enhanced (a) Li-ion conduction facilitated by unique Li-disorder induced by fluorine and other halogen co-dopants, and (b) stability against Li-anode owing to formation of a stable solid-electrolyte interface containing conductive species (Li3P), alongside LiCl and LiF. We will discuss these results in the context of accelerating design of novel solid-state electrolytes for long-lived, stable, and high-energy density SSLSBs.

Research on Advanced Treatment Technology of Fluorine Containing Wastewater from Graphite Production

With the gradual improvement of environmental emission requirements in China, the graphite industry is facing environmental pressure from advanced treatment. This article first conducted a study on the current status of advanced treatment technology for fluorinated wastewater. Subsequently, a single defluorination agent experiment was conducted, and it was found that compared to several agents used in the experiment, such as PAC, PAFS, and CaCl2, PAC had the best defluorination effect. The optimization of PAC conditions showed that its optimal reaction pH was 7, and equilibrium could be achieved after 3 minutes of reaction. The study also conducted orthogonal experiments with mixed salts, and the best conditions for the combination of fluoride removal agents were found to be PAC adding 400 mg/L, CaCl2 adding 400 mg/L, PAFS adding 200 mg/L, which can remove fluoride to 0.92 mg/L, below 1 mg/L, meeting the Class III water standard in the " Environmental quality standards for surface water ".The SEM image of the sludge generated by the reaction between the composite fluoride removal agent and fluoride containing wastewater shows a larger particle size of up to 50 μm which is beneficial for the separation and removal of sludge. The generated sediment sludge is mainly composed of Al, Fe, Ca, O, and Si according to EDS results, and belongs to general industrial solid waste.

A New Enthalpy of Formation Test Set Designed for Organic Fluorine Containing Compounds (Adv. Theory Simul. 8/2022)

A New Enthalpy of Formation Test Set for Finding Organic Fluorine Containing Compounds Density functional theory often performs worse predicting gas phase enthalpy of formation for fluorine compounds than it does for other systems. The numerical bias somewhat lacks a systematic quantification; the evaluation of various commonly used computational levels will facilitate research on fluorine chemistry. In article 2200093, Si, Yu and co-workers propose a new test set for fluorine containing compounds, and quantitatively analyze the differences induced by various computational levels and strategies.

Solvent Dependency in Stereoselective δ‐Lactam Formation of Chiral α‐Fluoromalonate Derivatives: Stereodivergent Synthesis of Heterocycles with Fluorine Containing Stereocenters Adjacent to Tertiary Stereocenters

AbstractThe discovery and investigation of solvent dependency in stereoselective intramolecular amidation of chiral 5‐aminofunctionalized‐2‐fluoromalonate ester derivatives, which gives access to highly functionalized δ‐lactams with a quaternary fluorine‐containing stereocenter, is disclosed. Experimental work together with density functional theory calculations led to understanding of how to direct and switch the stereochemical outcome of the stereoselective δ‐lactam formation. The merging of this solvent‐dependent stereoselective switch with asymmetric catalysis and cascade reactions gives access to an unprecedented strategy for stereodivergent synthesis of all possible stereoisomers of fluorine‐containing stereocenters adjacent to tertiary stereocenters of a wide range of heterocyclic compounds with 95‐>99% ee in one‐pot. It is also useful for application in total synthesis of fluorine‐containing pharmaceuticals.magnified image

A Potassium Based Fluorine Containing Bioactive Glass for Use as a Desensitizing Toothpaste.

Potassium releasing bioactive glasses (BAGs) may offer improved relief for dentine hypersensitivity compared to conventional sodium containing BAGs by releasing K+ ions for nerve desensitization and occluding dentinal tubules to prevent fluid flow within dentinal tubules. Potassium oxide was substituted for sodium oxide on a molar basis in a fluoride containing BAG used in toothpastes for treating dentine hypersensitivity. The BAG powders were then immersed in an artificial saliva at pH 7 and tris buffer and the pH rise and ion release behavior were characterized by ICP-OES and ISE. The potassium and sodium containing BAGs were characterized by XRD, DSC, FTIR and NMR. Both BAGs presented amorphous diffraction patterns and the glass transition temperature of the potassium glass was higher than that of the sodium glass. The 31P MAS-NMR spectra indicated a peak at 2.7 ppm corresponding to apatite and a small peak at −103 ppm indicated crystallization to fluorapatite. Both BAGs dissolved and formed apatite at similar rates, although the dissolution of the potassium glass was slightly slower and it released less fluoride as a result of partial nanocrystallization to fluorapatite upon quenching. The potassium release from the potassium ions could potentially result in nerve deactivation when used in toothpastes.

Designing a Transparent and Fluorine Containing Hydrogel.

Physical hydrogels are supramolecular materials obtained by self-assembly of small molecules called gelators. Aromatic amino acids and small peptides containing aromatic rings are good candidates as gelators due to their ability to form weak bonds as π-π interactions and hydrogen bonds between NH and CO of the peptide chain. In this paper we show our results in the preparation of a transparent hydrogel that was obtained by self-assembly of a fluorine-containing dipeptide that relies on the additional formation of halogen bonds due to the fluorine atoms contained in the dipeptide. We used Boc-D-F2Phe-L-Oxd-OH (F2Phe = 3,4-difluorophenylalainine; Oxd = 4-methyl-5-carboxy-oxazolidin-2-one) that formed a strong and transparent hydrogel in 0.5% w/w concentration at pH = 4.2. The formation of a hydrogel made of unnatural fluorinated amino acids may be of great interest in the evaluation of patients with parkinsonian syndromes and may be used for controlled release.

Synthesis, Cytotoxicity Evaluation and Molecular Docking of Fluorine Containing Hexahydroquinoline-3-Carbonitrile Derivatives.

Fluorine containing hexahydroquinoline-3-carbonitrile derivatives were found to have potent cytotoxicity. Furthermore, fluorine can modulate pharmacokinetic and pharmacodynamic profile of drugs. Hence, new derivatives containing fluorine were explored as potential cytotoxic agents. Difluoro substituted compounds containing aromatic/heteroaromatic rings were designed, synthesized and screened for in vitro cytotoxicity on cancer cell lines. The active compounds were subjected to docking on Mcl-1 and ADME/T prediction. The synthesized compounds were characterized using various spectral techniques like FT-IR, 1H NMR, 13C NMR and Mass spectra. Compounds were screened for cytotoxicity on NCI-60 cell lines at the National Cancer Institute. The active compounds were evaluated additionally by MTT and SRB assay. Compounds (6l and 6o) showed maximum cytotoxicity with (% GI) of 69 and 63.7 at 10 μM drug concentration, respectively. Compound 6i showed potent cytotoxicity with GI50 of 7.2 μM against Ishikawa cell line. Compound 6o was nearly as active as a reference with IC50 of 9.39 μM and 13.54 μM against HT-29 and HCT-116, respectively, and compound 6l also showed equal potency to that of reference with IC50 of 9.66 μM against Caco-2. Compounds 6i, 6o and 6l showed high docking scores, suggesting their cytotoxicity. Furthermore, ADME/T prediction revealed that all the compounds had drug-likeness properties. Enhanced lipophilic interaction of compounds due to the presence of fluorine in compounds 6i and 6l was revealed during the docking study. Compound 6i can be explored as a lead molecule against other endometrial cancer in futuristic drug development.

Synthesis And Study of Fluorine Containing Kagan's Amides as Chiral Solvating Agents For Enantiodiscrimination of Acids by NMR Spectroscopy

AbstractThe Kagan's amide is used as chiral solvating agent to discriminate the signals of optically active analytes in NMR spectroscopy. Three fluorinated derivatives of this amide are prepared and studied for their comparison of chiral recognition of different analytes by NMR analysis. The single crystal X‐ray analysis of the derivatives along with the details of their CSA activity is presented. The analysis is sufficiently accurate to establish a relationship between the calculated and observed values, suitable for determining the enantiomeric excess of samples of unknown purity.

An Efficient and Green Synthesis of Fluorine Containing Benzo[a]xanthen-11(12H)-ones and Evaluation of their Anticancer Activity

A facile and an efficient procedure has been developed by one-pot condensation of naphthalene-diols, fluoro substituted benzaldehydes and cyclic 1,3-dicarbonyl compounds for the synthesis of fluorine containing benzo[a]xanthen-11(12H)-ones under the catalyst and solvent-free conditions. All the synthesized compounds were characterized by IR, NMR (1H & 13C) and mass spectrometry. Several advantages offer the present approach, such as, shorter reaction time, low cost, anticipation of toxic solvents and catalyst, higher yield of products and durability of substrate range. On the other hand, anticancer activity was also performed for the title compounds which demonstrated a significant activity on selected cancer cell lines.

Highly Heat-Resistant Materials for Microelectronics: Hydrodynamic, Optical, and Conformational Properties of Fluorine Containing Poly(Amido-ortho-Hydroxy Amide)

The polycondensation of the mixture of diamines 5,5-methylene bis(2-aminophenol) and 4,4-(hexafluoroisopropylidene)dianiline (molar ratio 0.8:0.2) with isophthaloyl dichloride was used to synthesize poly(amido-o-hydroxy amide) (POA-F) - new heat resistant binder of the composites for microelectronics. The copolymer was fractionated, its hydrodynamic, optical, and conformational properties were researched, and molecular masses (ММ) of the fractions were defined. The polydispersity index was estimated. Based on experimental data, calculation of the size of a segment of Kuhn characterizing degree of an intramolecular orientation order and value of coefficients of the equation of Mark-Kuhn-Hauvink for viscometric and diffusion data were performed. It was demonstrated that introducing 20 mol % of the monomer with -CF3-groups does not lead to any changes in conformational properties of the macromolecules and does not change the degree of intramolecular orientational order (the Kuhn segment length). Optical characteristics of POA-F solutions are virtually similar to the corresponding values for POA prepared with the use of single amine-containing component-5,5-methylene bis(2-aminophenol). The received MM distribution for POA-F (prepolymer) provided the solubility of its films in alkaline solutions. The heat resistance (τ5 and τ10-temperatures corresponding to 5% and of 10% PBO-F mass loss of a polymer) of the powders and the films of PBO, PBO-F were determined. The electrophysical parameters-dielectric permittivity (e) and dielectric loss tangent (tan δ) of the PBO-F films decreased down to 3.30 and 0.017, in comparison 3.40 and 0.025 for PBO respectively.

Investigation of Protective Surface Film Behavior of Fluorine Containing Cover Gas Parameters on Molten Magnesium Alloy

Ergimis magnezyumun korunmasi, mevcut ve potansiyel magnezyum kullanicilari icin en onemli konulardan biridir. Pahali metal kayiplarinin en az seviyeye indirilmesinin yani sira guvenlik gibi nedenlerinden de oturu, etkili bir ergiyik koruma sistemi gereklidir. SF6, son derece yuksek bir kuresel isinma potansiyeline sahip oldugundan, HFC-134a bircok uygulamada etkili bir cozumdur. Bu calismada, HFC-134a/N2 atmosferi altinda ergimis AZ91A alasiminda olusan yuzey filmleri, farkli ergimis metal sicakliklari, temas sureleri, konsantrasyonlari ve koruyucu gaz debileri gibi cesitli parametrelerde incelenmektedir. Optimum islem parametrelerinin belirlenmesi icin Taguchi deneysel tasarim yontemi kullanilmistir. Deneyler neticesinde elde edilen yuzey filmleri optik mikroskop ile analiz edilmistir. Proses parametrelerinin ergiyik uzerinde en iyi koruyucu tabaka saglayanlari; 60 dakikalik temas suresi, 660 °C ergimis magnezyum sicakligi, % 0.30 hacimsel gaz konsantrasyon ve 600 l/h'lik koruyucu gaz karisim debisi olarak belirlenmistir.

Photoinduced Nonstabilized Azomethine Ylide Formation for the Preparation of Fluorine Containing Pyrrolidines.

A mild and reproducible method for the formation of a nonstabilized azomethine ylide was developed by photoinduced reaction catalyzed with eosin Y under green light irradiation. Resulting 1,3-dipole was trapped with fluoroalkenes, fluoroalkylated alkenes, and representative dipolarophiles to access pyrrolidine scaffolds, including spirocyclic compounds. The mechanism involved in this transformation was investigated, showing clearly a catalytic redox cycle with eosin Y.

A Versatile Water-Stable Fluorine Containing Organometallic Lewis Acid Used in Green Synthesis of 1,3-Oxazine Scaffolds at Room Temperature

A simple, straightforward, and highly efficient one-pot multicomponent synthesis of pharmaceutically interesting [1,3]-oxazine derivatives has been developed using iron(III) trifluroacetate ([Fe(CF3CO2)3]) as Lewis acid in an aqueous sodium dodecyl sulfate (SDS) micellar medium. The salient features of the present protocol are mild reaction conditions, use of aqueous SDS micellar medium, good yields, eco-friendly standards, easy isolation of products, no column chromatographic separation and reusability of catalytic system. The synthesized some chromeno[1,3]oxazine derivatives were tested for their antioxidant activity using free radicals DPPH method. The screened compounds showed moderate to good activity on comparison with ascorbic acid.

Modification of Epoxy Resin with a Phosphorus, Nitrogen, and Fluorine Containing Polymer to Improve the Flame Retardant and Hydrophobic Properties

AbstractTargeting high‐effective modification of flame retardant epoxy resin, elements including phosphorus, nitrogen, and fluorine are simultaneously incorporated into a polymer named as PFNP. A certain amount of amino groups are preserved on PFNP chains to participate in the curing of epoxy resin. The reactive groups and segments contain 9,10‐dihydro‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO) endowed PFNP with good compatibility in epoxy resin. The proper addition of PFNP improves the mechanical property and Tg values of epoxy resins. The limiting oxygen index values of EP/PFNP increases while the peak heat release rate, heat release capacity, and total heat release values reduce after introduction of PFNP. Samples with contents of PFNP higher than 5 wt% reach UL‐94 V‐0 rating without dripping. Notably, the migration effect of trifluoromethyl (CF3) groups not only increases the water contact angles, but also reduces the dielectric constants of epoxy resins.

Synthesis and Antimicrobial Activity of Fluorine Containing Pyrazole-clubbed Dihydropyrimidinones

In the present communication synthesis of pyrazole-containing dihydropyrimidinone motifs (4a-o) and their antimicrobial activity and cytotoxicity were reported. The newly synthesized compounds were characterized using infrared, proton nuclear magnetic resonance, carbon-13 nuclear magnetic resonance and mass spectral techniques. Compounds 4b, 4c, 4f, 4g, 4i and 4j were the most active derivatives identified during antimicrobial activity screening. On the basis of antibacterial activities, it was observed that compounds 4b and 4c exhibited activity against methicillin resistant Staphylococcus aureus with minimum inhibitory concentrations of 12.5 and 6.25 µg/ml, respectively. From structure activity relationship studies, it could be concluded that electron withdrawing groups played a crucial role in enhancing antimicrobial and cytotoxic effects of title compounds. In addition, the results of the cytotoxicity studies indicated that compounds 4b, 4c, 4g and 4j possessed lower levels of cytotoxicity.

Erratum to: X-ray Induced and Thermostimulated Luminescence of new Fluorine Containing Compounds (Potential Luminophores, Scintillators and Dosimeters).

X-ray induced luminescence spectra in optical range of wave-lengths (200–700 nm) and thermoluminescence curves for fluoride, fluorosulphate, fluorophosphate and fluorooxalate compounds of the titanium subgroup elements with alkali metals and ammonium have been obtained. Influence of annealing and repeated X-raying on luminescence (XRL) spectra of a number of compounds has been examined. Alloy additives influence on fluorine compounds XRL spectra has been examined. Most of compounds being under study may be used as X-ray luminophores, scintillators and dosimeters. The highest intensity of luminescence was achieved for such compounds as K2ZrF6, Cs2ZrF6, Rb2ZrF6 (especially for doped K2ZrF6), K2HfF6 and CsZr2(PO4)3. Radiation drifting to long-wave range for a number of fluorophosphatezirconates in comparison with fluorides may be a positive moment in making luminophores on their base.

X-Ray Induced and Thermostimulated Luminescence of New Fluorine Containing Compounds (Potential Luminophores, Scintillators and Dosimeters).

X-ray induced luminescence spectra in optical range of wave-lengths (200-700nm) and thermoluminescence curves for fluoride, fluorosulphate, fluorophosphate and fluorooxalate compounds of the titanium subgroup elements with alkali metals and ammonium have been obtained. Influence of annealing and repeated X-raying on luminescence (XRL) spectra of a number of compounds has been examined. Alloy additives influence on fluorine compounds XRL spectra has been examined. Most of compounds being under study may be used as X-ray luminophores, scintillators and dosimeters. The highest intensity of luminescence was achieved for such compounds as K2ZrF6, Cs2ZrF6, Rb2ZrF6 (especially for doped K2ZrF6), K2HfF6 and CsZr2(PO4)3. Radiation drifting to long-wave range for a number of fluorophosphatezirconates in comparison with fluorides may be a positive moment in making luminophores on their base.

A Study of Void Formation in Fluorine Containing Plasma Activated Wafer Bonding

Plasma activated bonding is one of promising candidates in wafer bonding field. In the past decade, much progress in terms of plasma generation, plasma treatment parameters, and annealing conditions has been achieved to allow high strength bonding at low temperatures with minimal defects. Since wafer bonding is often used as a middle process during device manufacturing, subsequent heated (or annealing) processes are inevitable for bonded wafers. However, void generation in annealing process (known as “annealing void”) is a serious problem in plasma activated bonding, especially for Si/Si wafer pairs. In particular, voids more frequently occur and are significantly severer as the wafer sizes further increase. Recently, our group has developed a fluorine activated bonding process enabling strong bonding of Si/Si bonded pairs (~2.2 J/m2 in surface energy) even at room temperature (~25ºC) without requiring annealing by introducing a small amount of carbon tetrafluoride (CF4) into oxygen plasma treatments. It seems that the fluorinated oxide allows water and hydrogen to diffuse out more easily from the interface at room temperature. But we have no idea how voids would be generated in elevated temperatures during subsequent annealing process. In this work, we demonstrate a quantitative evaluation of the void formation. As a comparison, void generation in the samples prepared by O2 plasma activated bonding is also systemically investigated. The void formation model is proposed to gain insight the mechanism of the fluorine containing plasma activated bonding. 8-inch silicon wafers (i.e. 200-mm diameters) were used in the experiments. To inspect void formation, a couple of bonded wafer pairs were prepared with different plasma treatment conditions. All the bonded wafer pairs were heated at 200, 300, 400, 500, 600, 700, and 800ºC for 8 h in ambient air. The heating steps do not aim to improve the bonding strength, but to investigate void formation at high temperatures. The IR imaging system was mainly used to characterize the voids in bonded pairs. To track the void emergence and growth, the digital image processing was employed to calculate void densities over the entire bonded wafer pairs. Water contact angle and x-ray photoelectron spectroscopy (XPS) measurements were made to investigate the plasma effects prior to bonding. In conclusion, we found adding fluorine to oxygen plasma could effectively mitigate void formation in subsequent annealing process. Moreover, the plasma treatment time is a vital parameter to optimize the bonding strength as well as the void generation. Long plasma treatment may produce more porous surfaces and introduce undetected microdefects. Consequently, a short fluorine containing plasma treatment (e.g. ~10 s) is suitable to remove organic contaminants, it is thus nearly void-free at the bonding interfaces during heating from 200 to 800ºC. In practice, an optimum treatment time depends on the application requirements. Figure 1

A Study of Void Formation in Fluorine Containing Plasma Activated Wafer Bonding

A quantitative evaluation of void formation in the fluorine containing plasma activated wafer bonding is demonstrated. Results shows adding a small amount of carbon tetrafluoride (CF4) into oxygen plasma could effectively mitigate void formation in subsequent annealing process. Moreover, long plasma treatments (e.g. >60 s) may produce more porous surfaces and introduce undetected microdefects. Therefore, a short fluorine containing plasma treatment (e.g. ~10 s) is able to remove organic contaminants with fewer defects and the bonding interfaces are nearly void-free during heating from 200 to 800ºC. A void formation model is proposed to gain insight the mechanism of the fluorine containing plasma activated bonding.

Physics and Chemistry of the Hydrogen Fluoride Production Process from Fluorine Containing Waste

The impact of the aluminum industry wastes on the environment is established. The resource efficient method of aluminum industry fluorine-containing wastes processing, which includes wastes oxidizing roasting to remove carbon component and the interaction of fluorine- containing particles with sulfuric acid in order to produce hydrogen fluoride, is considered. The economic and environmental effect of the proposed processing method is substantiated.