Fluorine chlorine with aluminum chloride

When hexafluorocyclobutene is treated with aluminum chloride, all fluorine atoms are replaced by chlorine. On treatment with aluminum bromide, all are replaced by bromine. The products are hexachlorocyclo-butene and hexabromocyclobutene, respectively. The reason for this quite unexpected reaction may be the difference in the strength of carbon-fluorine bond and aluminum-fluorine bond. As the aluminum-fluorine bond (595 kJ/mol, 142 kcal) is stronger than the carbon-fluorine bond (443 kJ/mol, 106 kcal), the lower reaction enthalpy may be the driving force for the halogen exchange [40]. 

Compounds containing fluorine and chlorine are also donors to BF3. Aqueous fluoroboric acid and the tetrafluoroborates of metals, nonmetals, and organic radicals represent a large class of compounds in which the fluoride ion is coordinating with trifluoroborane. Representative examples of these compounds are given in Table 5. Coordination compounds of boron trifluoride with the chlorides of sodium, aluminum, iron, copper, 2inc, tin, and lead have been indicated (53) they are probably chlorotrifluoroborates. 

A similar type of catalyst including a supported noble metal for regeneration was described extensively in a series of patents assigned to UOP (209-214). The catalysts were prepared by the sublimation of metal halides, especially aluminum chloride and boron trifluoride, onto an alumina carrier modified with alkali or rare earth-alkali metal ions. The noble metal was preferably deposited in an eggshell concentration profile. An earlier patent assigned to Texaco (215) describes the use of chlorinated alumina in the isobutane alkylation with higher alkenes, especially hexenes. TMPs were supposed to form via self-alkylation. Fluorinated alumina and silica samples were also tested in isobutane alkylation,... 

It has been suggested that the carbon atom in the carbonium ion which is usually represented as containing only six electrons in its outer shell may actually contain six of its own electrons and two electrons which are donated by chlorine atom from aluminum chloride or, presumably, a fluorine from boron fluoride (N. V. Sidgwick, private communication to Hunter and Yohe, 17). Combination with a second molecule of olefin would then involve the breaking of the carbon-chlorine coordinate bond and the formation of a carbon-carbon bond. 

The organozinc intermediate thus formed reacts with aldehydes as Grig-nard reagents do to form alcohols. In the presence of aluminum chloride, elimination of chlorine and fluorine from the vicinal carbons of the dichlorotrifluoroethyl group generates halogenated allylic alkoxides that are protonated to allylic alcohols, in the present case J, 2-chloro-3,3-difluoro-1 -phenylpropen-2-ol [114]. 

SAFETY PROFILE A highly corrosive irritant to the eyes, skin, and mucous membranes. Mildly toxic by inhalation, Explosive reaction with alcohols + hydrogen cyanide, potassium permanganate, sodium (with aqueous HCl), tetraselenium tetranitride. Ignition on contact with aluminum-titanium alloys (with HCl vapor), fluorine, hexa-lithium disilicide, metal acetylides or carbides (e.g., cesium acetylide, rubidium ace-tylide). Violent reaction with 1,1-difluoro-ethylene. Vigorous reaction with aluminum, chlorine + dinitroanilines (evolves gas). Potentially dangerous reaction with sulfuric acid releases HCl gas. Adsorption of the acid onto silicon dioxide is exothermic. See also HYDROGEN CHLORIDE (AEROSOL) and HYDROCHLORIC ACID. 

Alcoa process. A more efficient method of producing aluminum from bauxite that requires one-third less electric power than the Hall process. Alumina is reacted with chlorine, the resulting aluminum chloride yielding the metal and chlorine on electrolysis. No fluorine is required in the process. Prototype plants are under development. 

ARSENIOUS ACID or ARSENIOUS OXIDE or ARSENITE (1327-53-3) AsjOj Noncombustible solid. Reacts, possibly violently, with acids, aluminum, aluminum chloride, chlorine trifluoride, chromic oxide, fluorine, fluorides, halogens, hydrogen fluoride, mercury, oxygen fluoride, phosphorus pentoxide, rubidium acetylide, sodium chlorate, sodium hydroxide, sulfuric... 

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