Dietmar Peters

Symptoms and treatment of hydrogen fluoride injuries

Abstract Accidents with hydrogen fluoride are causes of the most hazardous injuries in laboratories. The effects of HF on human tissues are substantially different from those of ordinary acids. Therefore, the paper deals with the symptoms, first-aid and medical treatment of lesions caused by skin contact, inhalation or ingestion of HF. Furthermore, selected cases of accidents with hydrogen fluoride are reported to exemplify the unique dangers of such events. Some proper protection measures are also described.

Sonochemical treatment of natural ground water at different high frequencies: preliminary results

Naturally occurring ground water polluted by highly volatile chlorinated compounds, with 1,2-dichloroethane as the main contaminant, was sonicated with high frequency ultrasound (361, 620 and 1086 kHz) in order to investigate if results from studies performed with single model compounds in water can be applied to a natural ground water. It was shown that the treated highly volatile halogenated hydrocarbons are almost completely destroyed by ultrasound in natural ground water within 60 min. It also transpired that the naturally occurring inorganic components and gases in the ground water play an important role.

Sonolytic degradation of volatile pollutants in natural ground water: conclusions from a model study.

In order to evaluate the possibilities of an ultrasound-based cleaning technology, the effects of sonication on pollutants in a contaminated natural ground water were investigated. After the discussion of the results from this model study on the sonolytic degradation of volatile organic compounds, some consequences are reported and the important role of water components is described. Furthermore, the use of sonication as a cleaning technology for polluted water is discussed based on the conclusions from this study.

Perfluorozinc aromatics by direct insertion of zinc into C–F or C–Cl bonds

Abstract For the first time perfluoroaromatic organozinc compounds were obtained by direct action of zinc on C–F bonds in the presence of metal salts (SnCl 2 , CuCl 2 , ZnBr 2 ). The reactions are accelerated by ultrasound. The scope of the method can be extended to polyfluoroaromatics which contain other halogen atoms (Cl) in the aromatic ring.

Organofluorine compounds and fluorinating agents Part 17: Sonochemical-forced preparation of perfluoroalkanals and their use for non-conventional acetalations of carbohydrates

Abstract The homologous 1-iodo-perfluoroalkanes 1a-1c and α,ω-dibromo-perfluoroalkanes 4a, 4b were carbonylated with DMF in the presence of Al/SnCl 2 Al/PbBr 2 under sonication in a short reaction time. The hydrated aldehydes 2a-2c and 5a, 5b respectively were obtained in good yields allowing dehydration to 3a-3c and 6a, 6b . Some of the fluorinated aldehydes were selected as substrates in a Wittig-Horner olefination assisted by ultrasound and in non-conventional acetalations of methyl α- l -rhamnopyranoside ( 9 ). Thus, ( E )-1-perfluorooctyl-2-phenylsulphonyl-ethene ( 8 ) was prepared from 3c and the phosphonate 7 by Wittig-Horner synthesis. Acetalations of 9 were carried out with the aldehydes ( 3a, 3b, 6a ), hydrated aldehydes ( 2a, 2b ), and the aldehyde hemiacetal 12 respectively, in the presence of dicyclohexylcarbodiimide (DCC). In all cases, a selective epimerization was observed at the C-atom 3 of the monosaccharide, i.e. polyfluoroalkylidenated 6-deoxy-α- l -altropyranosides 10,11,13 , and 14 were obtained.

Micellen in wasserfreiem fluorwasserstoff v. aggregation von amphiphilen alkylammoniumfluoriden und tensioaktiven monosacchariden

Abstract The present paper describes the behaviour of amphiphiles in anhydrous liquid hydrogen fluoride. After a brief introduction describing some physico-chemical properties of HF, the aggregation of surfactants having an onium-structure and amphiphiles based on carbohydrates is discussed. The critical micelle concentrations (c.m.c.) in HF determinated by solubilization of hydrocarbons are 10 to 15 times greater than those in water. Special attention is given to the equilibria occuring in carbohydrate/hydrogen fluoride solutions.

Reactions with and in anhydrous hydrogen fluoride. Part 6. Reactions of peracetylated long-chain 3-O-(n-alkyl)- and 4,6-O-(n-alkylidene)-D-glucosyl fluorides in anhydrous hydrogen fluoride systems

Abstract The 2,4,6-tri-O-acetyl-3-O-alkyl- D -glucopyranosyl fluorides (1–5) undergo rearrangement in anhydrous hydrogen fluoride to give the 1,2:5,6-diacetoxonium ions (11–15). On further reaction, the latter (except the methyl derivative 5) are dealkylated and further rearrange to give the 2,3:5,6-diacetoxonium ion of the D -mannofuranosyl fluoride 19. The 2,3-di-O-acetyl-4,6-O-alkylidene- D -glucopyranosyl fluorides (22 and 23) were prepared from the corresponding 1-O-acetates by treatment with hydrogen fluoride in nitromethane.

Fluorination of organic compounds with ultrasound

This paper focuses on the use of ultrasound in the synthesis of organofluorine compounds by introduction of fluorine atoms or fluorine containing moieties. After a short introduction about sonochemical effects, reactions involving trifluoromethyl and higher perfluoroalkyl derivatives are described. Furthermore, the preparation of monofluorinated molecules is reported.

SYNTHESIS OF VINYL SULFONES FROM ARYL METHYL KETONES UNDER SONOCHEMICAL CONDITIONS AND FORMATION OF ALLYL SULFONES

Abstract An efficient synthesis of vinyl sulfones 3a-o from aryl methyl ketones 2 bearing an electron withdrawing group and the phosphonic ester 1 under sonochemical conditions is reported. These compounds are generally obtained as an E/Z mixture. Formation of the allyl sulfones 4 is also observed.

New simultaneous fluorination/acylation agents for sugar derivatives

Abstract One of the anomeric Glucosylfluorides can be prepared selectively in a HF/MeNO 2 (2 : 10) system at temperatures of −20°C and a reaction time of a few minutes. The following example shows, that acid-labile acetal groups are not cleaved: Three component systems of anhydrous hydrogen fluoride, carboxylic acid anhydrides as well as different volumes of the polar solvent nitromethane are found to be new, homogeneous agent- catalyst-solvent media, which are wide modifiable in the reactivity. Such systems can be used to prepare the desired glycosylfluorides (with pyranose — or furanose — structure) on a short way. Compounds of this type are known as interesting glycosyl- donors, for instance R = Alkyl, Benzyl, Allyl, Mesyl, p-Tosyl, Acyl