A. Dimitrov

Persistent fluorocarbon radicals generated by elemental and electrochemical fluorination

Abstract Stable fluorocarbon radicals ware obtained by fluorination of branched fluoro-olefins and unsaturated partially fluorinated tertiary amines. As a fluorine source, elemental fluorine as well as the electrochemical fluorination process (ECF) in anhydrous hydrogen fluoride (AHF) were used. The persistent radicals were investigated by ESR spectroscopy concerning their structure and stability. ECF-generated fluorocarbon radicals give some evidence of intermediately formed atomic fluorine as a key factor of the AHF-based electrochemical process. These findings favour and electrofluorination mechanism similar to that of elemental fluorine. Because of their unusual stability, the radicals can be used as spin markers and to obtain 2D images by using an ESR tomographic technique. Stabilized with emulsifiers, they form stable aqueous emulsions.

Current balance of the electrochemical fluorination of a trialkylamine

Abstract The electrochemical fluorination of dibutylmethylamine was studied. All the fluorination products formed, liquid, gaseous, and dissolved in HF, and also the hydrogen evolved were quantitatively determined. From either their formulae or their relative fluorine contents the amount of current necessary for their formation was estimated. Altogether, the fluorination products determined cover about 86 – 92 % of the current applied. A major part of the current was consumed by production of polyfluorinated compounds, which remained dissolved in the hydrogen fluoride.

Investigations on the electrochemical fluorination of amines

Abstract Electrochemical investigations of dibutylmethylamine (DBMA) and of polyfluorinated amines derived from DBMA by electrochemical fluorination in anhydrous HF (ECF) were carried out. From the results of these investigations, which gave no evidence of a direct involvement of the organic compounds in the anodic process, and from other experimental facts discussed, it follows that the formation of an ‘active fluorine’ at the anode is very probably the primary step in the ECF of amines.

On the electrochemical fluorination of aminoethers to give perfluoroaminoethers : possible candidates for blood substitutes

Abstract Aminoethers, ROC 2 H 4 NCH 2 CH 2 OCH 2 C H 2 (R = C 6 H 5 , C 6 F 5 , C 2 H 5 ), C 6 F 5 OC 2 H 4 N[CH 2 ] 5 , were electrofluorinated in anhydrous hydrogen fluoride, the corresponding saturated perfluoroaminoethers being the largest individual substances in each case. One of them, F-[4-(2-cyclohexyloxyethyl)morpholine], has promising properties as a blood substitute.

Electrochemical fluorination (ECF) of trialkylamines — an access to ECF mechanism☆

Abstract Many different types of investigations carried out during or in connection with electrochemical fluorination (ECF) of trialkylamines are discussed in terms of the ECF mechanism. These investigations include the type, properties and kinetics of the formation of perfluorotri-alkylamines and of their partially fluorinated intermediates, and also the formation of stable radicals. The results are in favour of an initially kinetically controlled fluorination by the fluorine formed and absorbed at the Ni NiF 2 anode.

On polyfluorinated, HF soluble compounds formed during the electrochemical fluorination of dibutylmethylamine

Abstract The electrochemicaI fluorination of dibutylmethylamine yields, besides other products, considerable amounts of polyfluorinated compounds which remain dissolved in HF. Since the occurrence of such compounds is a widespread phenomenon in ECF, their formation as well as their composition was studied. Whereas some partially fluorinated compounds are likely to be intermediates in the fluorination process, others remain inert toward further ECF. The latter have on average about 9 of the 21 H-atoms replaced by F, with almost no F at C-atoms adjacent to the N-atom.

On the electrochemical fluorination of triethylamine. Part 1. Formation and properties of partially fluorinated compounds

Abstract The electrochemical fluorination (ECF) of triethylamine (TEA) has been studied with respect to changes in the composition of the anhydrous hydrogen fluoride electrolyte. Depending on the current passed, different partially fluorinated compounds have been isolated and identified during ECF. The fluorine distribution in the TEA skeleton of these compounds shows a striking similarity to the product distribution known for free-radical halogenation processes.

Comparative fluorination of N,N-dialkylamidosulfonyl halides

Abstract N , N -Bis (trifluoromethyl) amidosulfonyl fluoride and lower fluorinated analogues can be obtained by electrochemical fluorination as well as by CoF 3 -fluorination of N , N -dimethylamidosulfonyl fluoride or chloride. The CoF 3 process is especially useful for the synthesis of lower fluorinated compounds. The new compounds are potential insecticides.

On the electrochemical fluorination of quaternary ammonium compounds. Part 1. Tetraalkyl ammonium salts

Abstract Tetraalkylated ammonium compounds, which are known to be very stable towards oxidative attack, can be electrofluorinated readily to yield perfluoro tertiary amines. Other than the enhanced formation of gaseous cleavage products, the electrofluorination proceeds similarly to that of other tertiary amines.

The Crystal Structure of a Phosphite Ozonide, C2H5C(CH2O)3PO3

The crystal structure of C2H5C(CH2O)3PO3 shows that this ozonide contains a symmetric, almost planar, four-membered PO3 ring with two crystallographically different, but otherwise essentially equal, molecules in the asymmetric unit cell.