Inorganic Fluorine Research Articles

Plasma polymer chemical gradients for evaluation of surface reactivity: epoxide reaction with carboxylic acid surface groups

Organic surfaces of specific chemistry can be fabricated using plasma polymerisation. A recently developed deposition approach allows gradients in surface carboxyl group concentration to be fabricated over a distance of 13 mm from a mixed acrylic acid/octadiene plasma. The utility of these surfaces in the investigation of the chemisorption of volatile specie using small area XPS analysis has been demonstrated using halogen-substituted epoxide molecules. The combination of automated small area XPS analysis and chemical gradients has been used to reduce the number of samples required by a factor of 20 compared with the traditionally employed one data point-one sample approach. We believe that chemical gradients are a flexible and widely applicable route to reducing the sample preparation load in such a study of adsorbate–surface reactivity. The reactivity of epoxy functionalities with surfaces is of great importance in the field of adhesion science; most high performance paints and adhesives are based on epoxy resins. Here, the inter-relationship between the amount of epoxide chemisorption and the carboxylic acid concentration is determined. It is apparent that the level of chemisorption is strongly dependent on the carboxyl concentration, exhibiting a threshold surface composition below which reaction was not observed. The influence of the halogen tag atom is made clear; it is shown that a fluorine tagged epoxide has enhanced reactivity compared to chlorine or bromine substituted epoxides. It is also observed that degradation of the epifluorohydrin molecule occurs to form an inorganic fluorine species at the plasma polymer surface.

Tyrosinase-catalyzed Oxidation of Fluorophenols

The activity of the type 3 copper enzyme tyrosinase toward 2-, 3-, and 4-fluorophenol was studied by kinetic methods and (1)H and (19)F NMR spectroscopy. Whereas 3- and 4-fluorophenol react with tyrosinase to give products that undergo a rapid polymerization process, 2-fluorophenol is not reactive and actually acts as a competitive inhibitor in the enzymatic oxidation of 3,4-dihydroxyphenylalanine (L-dopa). The tyrosinase-mediated polymerization of 3- and 4-fluorophenols has been studied in detail. It proceeds through a phenolic coupling pathway in which the common reactive fluoroquinone, produced stereospecifically by tyrosinase, eliminates an inorganic fluorine ion. The enzymatic reaction studied as a function of substrate concentration shows a prominent lag that is completely depleted in the presence of L-dopa. The kinetic parameters of the reactions can be correlated to the electronic and steric effects of the fluorine substituent position. Whereas the fluorine electron withdrawing effect appears to control the binding of the substrates (K(m) for 3- and 4-fluorophenols and K(I) for 2-fluorophenol), the k(cat) parameters do not follow the expected trend, indicating that in the transition state some additional steric effect rules the reactivity.

Determination of Inorganic Fluorine in High-Purity Silane

A method was proposed for determining inorganic fluorine in high-purity silane. The method is based on the hydrolytic extraction of fluorine as fluorides to the aqueous phase, followed by the analysis of the extract by ion chromatography with a conductometric detector. The detection limit for inorganic fluorine was 1 × 10–5mass %.

Inorganic fluorine chemistry, 1961–1999

The initial work on inorganic fluorine chemistry was the electrolytic production of elemental fluorine by using carbon anode. The study on carbon anode reaction, in particular, anode effect, was extended to the synthesis and properties of graphite fluorides and various types of graphite intercalation compounds. These works further led to the synthesis of new transition metal fluorides and oxide fluorides. The present review summarizes the reaearch works on inorganic fluorine chemistry done from 1961 to 1999.

On the use of HF as a reference for the comparison of stratospheric observations and models

Hydrogen fluoride (HF) is often used as a simple reference for other column observations of chemically active stratospheric species. However, seasonal and shorter timescale variations in column HF make its use as a reference more complicated. In this paper we characterize the expected magnitude of these variations in HF, and variations of ratio quantities involving HF, using a two‐dimensional (2‐D) photochemical model and two versions of a three‐dimensional (3‐D) transport model. The 2‐D model predicts that the column ratios HNO3/HF and HCl/HF increase from midlatitudes to the tropics, although this is very sensitive to HCl and HNO3 abundances in the tropical upper troposphere. Seasonal variations in vertical motion modifys the predicted ratios; for example, wintertime descent at high latitudes decreases HCl/HF. The ratio HNO3/HF at high latitudes is strongly modified by seasonal variations in the chemical partitioning of the odd nitrogen (NOy) species. We compare these model predictions with ground‐based Fourier transform infrared spectroscopy (FTIR) observations of HF along with HCl, ClONO2 and HNO3 obtained at eight northern hemisphere sites between October 1994 and July 1995. We investigate quantitatively how HF can be used as a tracer to follow the evolution of observations at a single station and to intercompare results from different stations or with photochemical models. The magnitude of the 3‐D model HF column agrees well with the observations, except on some occasions at high latitudes, giving indirect support for the important role of COF2 in the stratospheric inorganic fluorine budget. The observed day‐to‐day variability in the column ratios HCl/HF and HNO3/HF is much larger at high latitudes. This variability is reproduced in the 3‐D models and is due to horizontal motion. Short timescale vertical displacement of the species profiles is estimated to have a small effect on the column ratios. In particular, we analyze the usefulness of the observed column ratio (ClONO2 + HCl)/HF as an indicator for chlorine activation. Current measurement uncertainties limit the degree of activation which can be unambiguously detected using this observed quantity, but we can determine that chlorine‐activated air was observed above Aberdeen (58°N) on 6 days in late January 1995.

A Review of: “Inorganic Fluorine Chemistry; Toward the 21st Century”

A Review of: “Inorganic Fluorine Chemistry; Toward the 21st Century”

Inorganic fluorine chemistry: toward the 21st century: developed from a symposium sponsored by the Division of Fluorine Chemistry at the 203rd National Meeting of the American Chemical Society, San Francisco, California, April 5-10, 1992

Inorganic Fluorine Chemistry: Toward the 21st Century Thermodynamic Aspects of the Remarkable Oxidizing Capabilities of Fluorine-Lewis-Fluoroacid Mixtures Photochemical and Thermal Dissociation Synthesis of Krypton Difluoride Main-Group Fluorides with Coordination Numbers Greater than Six Heptacoordinated Main-Group Fluorides and Oxofluorides Monofluoroxenonium Hexafluorometalates XeF]+MF[6[- (M = As or Sb): A Course to Different Onium Cations Influence of Fluorine and Parahalogen Substituents on the Chemistry of Some Functional Groups Functionalization of Pentafluoro-*l]6-sulfanyl (SF[5) Olefins and Acetylenes Fluoro-Sulfur Anions: Transition States, Intermediates, and Reagents Quest for an Aromatic Silicon Species: An Unusual Geometry around Silicon in a 10-Si-5 Siliconate Reaction of SiH[4 with UF[6 and HF below 25 C: Fourier Transform IR Study Fluorinated Aldehydes and Their Polymers Synthesis and Chemistry of Perfluoro Macrocycles: Perfluoro Crown Ethers and Cryptands Alkali Metal Polyhydrogen Fluorides: Useful Halogen-Exchanges Media New and Revisited Transition Metal Chemistry of Fluoro-olefins and Fluorodienes Organometallic Chemistry of Fluorinated Isocyanides Synthetic, Structural and Reactivity Studies of Organocobalt(III) Compounds Containing Fluorinated Alkyl Ligands Perfluorovinyl and Perfluoroaryl Zinc and Cadmium Reagents: Preparation, Stability, and Reactivity Organic and Main-Group Chemistry of the 2,4,6-Tris(trifluoromethyl)phenyl Substituent: Kinetic Stabilization through Steric and Electronic Effects Reaction of Nonmetal Fluorides with Some Platinum Metal Complexes Large Polyfluorinated Anions Used To Generate Coordinative Unsaturation in Cations Stabilization of Unusual Cations by Very Weakly Basic Fluoro Anions Synthesis, Structure, and Reactivity of Highly Soluble Organotitanium Lewis Acids New Synthetic Routes to Cyclopentadienyluranium(IV) Fluorides: Redox and Atom-Abstraction Reactions Activation of Carbon-Fluorine Bonds by Oxidative Addition to Low-Valent Transition Metals Recent Developments in the Chemistry of Fluorinated Isopropoxides and Tertiary Butoxides (Fluoroaklyl)phosphine Coordination Chemistry

Increase of carbonyl fluoride (COF2) in the stratosphere and its contribution to the 1992 budget of inorganic fluorine in the upper stratosphere

Volume mixing ratio profiles of COF2 have been derived through most of the stratosphere between 30°N and 54°S from series of 0.01‐cm−1 resolution infrared solar spectra recorded in the occultation mode by the atmospheric trace molecule spectroscopy (ATMOS) instrument during the ATLAS 1 space shuttle mission of March–April 1992. When compared with similar results obtained from the ATMOS/Spacelab 3 mission of April–May 1985, the cumulative increase in the burden of COF2 in the middle and upper stratosphere was found to be 67% for that 7‐year time interval. By combining a subset of these COF2 results with upper stratospheric concentrations of HF also derived from the ATMOS observations, it was further found that the budget of inorganic fluorine above 35 km altitude increased by (6 ±10)% over the 1985–1992 time interval, which corresponds to an average exponential rate of increase of (6.7±1.1)% yr−1, or a linear rate of increase referenced to 1985 of (8.5±1.3) % yr−1 at the 1σ confidence level. The total inorganic F atom volume mixing ratio found in the upper stratosphere for 1985 and 1992 and the increase during this period mirror the rise in man‐made fluorine‐bearing compounds at the ground during the early to mid 1980s. This demonstrates the negligible impact of natural sources of fluorine, in particular volcanic activity, on the observed change of F in the upper stratosphere. Implications of the present findings and comparison with model results are discussed.

Health effects of fluorine and its compounds

Fluoride, the ionic form of fluorine, is a natural component of the biosphere and 13th most abundant element in the crust of the earth. It is, therefore, found in a wide range of concentrations in virtually all inanimate and living things. Many trace elements perform a definite function in human metabolism and the question of the value of fluoride, always found in the body, has been raised. Much evidence suggesting that the inclusion of fluoride in drinking water has beneficial as well as adverse effects on human health was obtained. Either alone or in combination with calcium and/or vitamin D, it is used in high daily doses for the treatment of osteoporosis. Although organic fluorine compounds are used in medicine and commerce, the inorganic fluorine compounds are of greater importance toxicologically because they are more readily available. The major pathway of fluoride elimination from the human body is via the kidney. When renal function deteriorates, the ability to excrete fluoride markedly decreases, possibly resulting in greater retention of fluoride in the body. At this point, more research is needed to evaluate the effects of physiological variables on the fluoride metabolism in humans.

無機フッ素の腎に及ぼす影響に関する実験的研究

無機フッ素の腎に及ぼす影響に関する実験的研究

Inorganic fluorides production in fluor treatment of phosphate raw material in the USSR

The manufacture of inorganic fluorine compounds by phosphate raw material treatment ranks in the USSR a significant place as to providing country with fluoride products. At present over 35% of technical fluoride salts in the country is produced by mineral fertilizers plants. P:F ratio in apatite cocentrate is 5.8, while its 4.1 in Karatau phosphate concentrate obtained by flotation. With due account of the commercially possible value of fluorine recovery (40–60%), fluorine reserves in phosphate rocks of the USSR 2–3 times exceed those in fluorspar. The fluorine utilization of phosphate raw materials is realized almost exclusively from Kola apatite concentrate. In the manufacture of fertilizers and phosphoric acid by the wet process, the off-gases containing fluorine are trapped in the scrubbing systems, the thus obtained silicohydrofluoric acid solutions are fed for further treatment with the formation of AlF3, Na3AlF6, Na2SiF6, K2SiF6, (NH4)zSiF6,NH4HF2 and NaF. The various fluoride production routes are used in the USSR, which secure in most of cases product quality meeting the requirements of world market. Moreover, the production processes of granular fluoride salts, calcium fluoride have been developed; in continuous operation are the plant production of anhydrous hydrogen fluoride and hydrofluoric acid from bifluoride-fluoride ammonium. The USSR is exporting aluminium fluoride, Na2SiF6 and is prepared to increase the export of fluorine products if the respective production lines are retrofitted.

Two‐dimensional model calculation of fluorine‐containing reservoir species in the stratosphere

Two‐dimensional model calculations have been carried out of the distributions of the fluorine‐containing reservoir species HF, CF2O, and CFClO. HF constitutes the largest fluorine reservoir in the stratosphere, but CF2O also makes an important contribution to the inorganic fluorine budget. CFClO amounts are most important in the tropical lower stratosphere. HF amounts increase with altitude throughout the stratosphere, while those of CF2O and CFClO fall off above their mixing ratio peaks due to photolysis. The model is in good qualitative agreement with observed vertical profiles of HF arid CF2O but tends to underestimate the total column of HF. The calculated CFClO distribution is in good agreement with the very limited data. The disagreement in the HF columns is likely due to small inaccuracies in the model's treatment of lower stratospheric photolysis of chlorofluorocarbons. The model results support the suggestion that CF2O may be heterogeneously converted to HF on the surface of polar stratospheric cloud particles. The model results also suggest that the quantum yield for photolysis of CF2O is near unity.

A sealed tube dry combustion method for ultramicrodetermination of fluorine in organic compounds

A sealed tube dry combustion method has been applied to ultramicrodetermination of fluorine in organic compounds. A sample below 1 mg is weighed in a thin quartz glass tube with one end closed and a small amount of sodium carbonate is placed in the same tube. Oxygen is then slowly blown into the tube and the open end is closed, forming a fine tip. The sealed tube is heated at 580 °C in an electric furnace for 1.5 h to decompose the sample. Inorganic fluorine reacts with sodium carbonate and the resultant fluoride is dissolved in an aqueous solution introduced in the sealed tube after breaking off of the fine tip. The fluoride ion is determined spectrophotometrically using lanthanum-alizarin complexone.

ChemInform Abstract: On the Role of Inorganic Fluorine Chemistry in the Study of Synthetic Metals

ChemInform Abstract: On the Role of Inorganic Fluorine Chemistry in the Study of Synthetic Metals

Inorganic fluorine chemistry, 1900–1945

Inorganic fluorine chemistry, 1900–1945

On the role of inorganic fluorine chemistry in the study of synthetic metals

The intercalation of metal hexafluorides (MF6) into graphite proceeds according to the reaction nC + MF6 → Cn+x(MF6−)x(MF6)1−x where x is the degree of charge transfer. The latter can be determined by magnetic measurements. It varies approximately linearly with the electron affinity of the MF6.The doping of polyacetylene by MF6 is believed to proceed by a similar reaction.

Developments in inorganic fluorine chemistry through noble-gas chemistry

The discovery of noble-gas compounds in 1962 quickly led to the isolation of four new simple fluorides, XeF 2, XeF 4, XeF 6 and KrF 2. All are clean fluorinating agents and this was recognized from the beginning [1]. Two have turned out to be particularly useful. Xenon difluoride has been extensively used in organic chemistry [2] and has also been instrumental in the development of new classes of inorganic compounds such as the transition-metal carbonyl fluorides [3] and chalcogenide fluorides [4]. Krypton difluoride has yielded new high oxidation-state fluorides and fluoride ions such as AuF 5 [5] and [BrF 6] + [6]. The value and further potential of noble-gas fluorides, especially XeF 2 and KrF 2, as fluorinating agents will be discussed.

ChemInform Abstract: FLUORINE DIFFUSION AND PHASE TRANSITION IN SUPERIONIC CONDUCTOR POTASSIUM PENTAFLUOROSTANNATE (KSN2F5) AS STUDIED BY FLUORINE‐19 NMR, ELECTRICAL CONDUCTIVITY AND DSC

Chemischer InformationsdienstVolume 14, Issue 34 Physical Inorganic Chemistry ChemInform Abstract: FLUORINE DIFFUSION AND PHASE TRANSITION IN SUPERIONIC CONDUCTOR POTASSIUM PENTAFLUOROSTANNATE (KSN2F5) AS STUDIED BY FLUORINE-19 NMR, ELECTRICAL CONDUCTIVITY AND DSC W. D. BASLER, W. D. BASLERSearch for more papers by this authorI. V. MURIN, I. V. MURINSearch for more papers by this authorS. V. CHERNOV, S. V. CHERNOVSearch for more papers by this author W. D. BASLER, W. D. BASLERSearch for more papers by this authorI. V. MURIN, I. V. MURINSearch for more papers by this authorS. V. CHERNOV, S. V. CHERNOVSearch for more papers by this author First published: August 23, 1983 https://doi.org/10.1002/chin.198334013Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume14, Issue34August 23, 1983 RelatedInformation

やさしいフッ素の化学 (I) : 無機フッ素化学のトピックス

やさしいフッ素の化学 (I) : 無機フッ素化学のトピックス

ChemInform Abstract: DEFECTS AND FLUORINE DIFFUSION IN SODIUM FLUOROBERYLLATE GLASS: A MOLECULAR DYNAMICS STUDY

Chemischer InformationsdienstVolume 12, Issue 49 Physical Inorganic Chemistry ChemInform Abstract: DEFECTS AND FLUORINE DIFFUSION IN SODIUM FLUOROBERYLLATE GLASS: A MOLECULAR DYNAMICS STUDY S. A. BRAWER, S. A. BRAWERSearch for more papers by this author S. A. BRAWER, S. A. BRAWERSearch for more papers by this author First published: December 8, 1981 https://doi.org/10.1002/chin.198149019AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume12, Issue49December 8, 1981 RelatedInformation