Heng-dao Quan

The synthesis of perfluoroamine using nitrogen trifluoride

Abstract The reactions of nitrogen trifluoride ( 1 ) with hexafluoropropene ( 2 ) in the presence of cesium fluoride (CsF) gave 2- ( 3 ) and 1-heptafluoropropyldifluoroamine ( 4 ) in moderate yields. Tetrafluoroethylene ( 6 ) and octafluoro-2-butene ( 8 ) similarly reacted with 1 to give corresponding products.

UTILITY OF SILICON TETRAFLUORIDE AS A CATALYST OF REACTIONS WITH XENON DIFLUORIDE : FLUORINATIONS OF PHENYL ALKENES AND BENZALDEHYDES

Abstract Application of silicon tetrafluoride to fluorinations with xenon difluoride as a catalyst is investigated. It was found that vic- difluorination of phenyl alkenes and transformation of benzaldehydes to difluoromethoxybenzenes using xenon difluoride are enhanced by silicon tetrafluoride.

Esterification of 1,2-dichloro-1,1,2-trifluoro-2-methoxyethane with AlFm(OH)3−m

Abstract Porous AlFm(OH)3−m was prepared by heating AlF3·3H2O. Methyl chlorodifluoroacetate was synthesized in 77% yield by the reaction of 1,2-dichloro-1,1,2-trifluoro-2-methoxyethane with AlFm(OH)3−m. The reaction mechanism was inferred in terms of surface property of AlFm(OH)3−m.

Fluorination of n-dodecane adsorbed on porous aluminium fluoride by gaseous fluorine

Abstract The reaction of fluorine with n -dodecane adsorbed on porous aluminium fluoride (PAF) proceeds with up to 90% selectivity for all monofluorinated dodecane and more than 30% selectivity for terminal fluorinated dodecane, which provides a novel means for preparing mono and terminal linear fluorinated alkanes. In the reaction, PAF with a large surface area is chosen as support to adsorb the linear hydrocarbon.

Fluorination of etheric substrates adsorbed on porous aluminium fluoride by gaseous fluorine

Abstract A novel fluorination procedure of etheric substrates adsorbed on porous aluminium fluoride (PAF) using gaseous fluorine has been investigated. The reaction of ethyl 1,1,2,2-tetrafluoroethylether 1 and 2-chloro-1,1,2-trifluoroethylmethylether 9 with fluorine proceeds with upto 58% selectivity for α -monofluorinated 1 and 96% selectivity for α -monofluorinated 9 . At the same time, charring can be avoided in the fluorination process.

Fluorination of chlorofluoroether using catalysts supported by porous aluminum fluoride

Abstract Reaction of 1,2-dichloro-1,1,2-trifluoro-2-methoxyethane with anhydrous hydrogen fluoride (AHF) was investigated in the presence of metal fluorides supported on porous aluminum fluoride (PAF). 2-Chloro-1,1,2,2-tetrafluoro-2-methoxyethane, a new compound, was prepared in 85% yield in the presence of CoF2/PAF. Methyl chlorodifluoroacetate was also obtained and its formation was discussed.

Preparation of tetrafluorohydrazine from nitrogen trifluoride with iron or iron(II) fluoride

Abstract Tetrafluorohydrazine (N 2 F 4 , 2 ) was synthesized from nitrogen trifluoride (NF 3 , 1 ) using iron. Through optimizing reaction conditions, a good yield of 2 was obtained at a temperature of 400°C. Furthermore, iron(II) fluoride, as metal fluoride, showed similar results in synthesizing 2 from 1 .

Synthesis of microporous fluorinated chromia with a sharp pore distribution

This paper reports a novel micro-porous fluorinated chromia with a sharp pore distribution from 0.5 nm to 1.5 nm. The mentioned fluorinated chromia has a 105.1 m2 g−1 surface area and an excellent chemical stability in the presence of strong corrosive media such as HF, HCl and thermo-stability under 300 °C. A facile process for preparing the target material is carried out by controlling the decomposition rate of urea in a solution of chromium chloride to obtain its precursor, chromia, which has a narrow pore distribution in the range from 0.5 nm to 1.5 nm. Then the chromia is treated with HF via vapor-phase fluorination to obtain porous fluorinated chromia. The prepared material has been used as a fluorination catalyst with a high catalytic activity, and could be a potential membrane material and sorption media.

Defluorination of homologous chlorofluoroethers to chlorofluoroacetates

Abstract The research was focused on the defluorination of chlorofluoroethers to corresponding esters using porous aluminum fluoride (PAF) or MF n /PAF. In the work up process, the product was easily separated from the reagent. Thus, the reaction would be a practical preparation method for polyfluorinated esters. Trifluoromethyl chlorodifluoroacetate was obtained by the reaction of 1,2-dichlorotrifluoroethyltrifluoromethyl ether with fuming sulfuric acid in 49% yield.