Antimony, reaction with alkyl halides

Reaction of 74 with alkyl halides gives 75 (equation 285 °). Triorganoantimony compounds containing allyl groups react with the iron complex 76 with elimination of the allyl moiety to give 77 (equation 286 ). Reaction of the tetracoordinate antimony ate complex 78 with the iron complex 79 gives 80, which has been characterized by X-ray analysis (equation 287 ). 

Arsenic and Antimony. Three studies of reaction mechanisms for tetrahedral antimony(v) compounds are reported. These are of the reaction of trimethylantimony sulphide (MegSbS) with alkyl halides, where a four-centre transition state seems possible, the reaction of R4Sb+ cations with alkoxide ions, and the ageing of antimonic acid in aqueous solution. Both thermal and photochemical decomposition of pentaphenylanti-mony have been investigated. Whereas the products of the photochemical reaction are numerous, though all derived from phenyl radicals, the... 

Like triorganoantimony(V) halides, derivatives of this class had also been prepared in the middle of nineteenth century169-171). The procedure adopted, which is still the principal method for preparing the tetraalkyl antimony halides involves the quaternization of trialkylantimony with an alkyl halide13,172). Since the triarylantimony as well as diaryl-alkylantimony can not be quatemized by alkyl halides, other methods13,21,23,98,173 179 e.g., the reaction of triphenylstibine, chlorobenzene and anhydrous aluminium chloride179), have been utilized to prepare these derivatives. 

Heating fluorocarboxylic acid halides to 550-650 C gives the corresponding alkyl halides as the main products." " When the reaction is carried out with an acyl fluoride in the liquid phase in the presence of antimony(V) fluoride, the decarbonylation takes place at a temperature of ca. 25 to 250 C." e.g. 7H-perfluoroheptanoyl fluoride gives under these conditions l//-perfluorohexane (1). ... 

Preparation of Alkyl Halides.—We have spoken of the formation of the alkyl halides by the direct action of the halogen upon the saturated hydrocarbon. In the case of chlorine this action takes place at ordinary temperatures as in the reaction between methane and chlorine in the sunlight. Bromine, however, does not act directly at ordinary temperatures but by heating in a sealed tube. Iodine does not act directly with the hydrocarbons. In any case the result is a mixture of several substitution products, and the method is not, therefore, of practical value. Where direct action does not occur the presence of iodine chloride or antimony chloride, which act as carriers, is necessary. The two reactions of most importance in the preparation of these compounds are those involving either alcohols or unsaturated hydrocarbons. These will be taken up when these compounds are studied. 

Various benzodioxa- and benzodithiastibepins (148 X = O or S, Y = alkyl or halide) have been isolated from reactions of the o-xylylene diols and dithiols with antimony(III) halides <87IZV423, 87IZV2342). Similar reactions with maleic or phthalic acid give cyclic diesters <84ZN(B)600,84ZN(B)754>. Detailed IR and Raman spectroscopic investigations have been performed on the cyclic dithiolates... 

Typical alkylation reactions are those of propane, isobutane, and n-butane by the ferf-butyl or sw-butyl ion. These systems are somewhat interconvertible by competing hydride transfer and rearrangement of the carbenium ions. The reactions were carried out using alkyl carbenium ion hexafluoroantimonate salts prepared from the corresponding halides and antimony pentafluoride in sulfuryl chloride fluoride solution and treating them in the same solvent with alkanes. The reagents were mixed at —78°C warmed up to — 20°C and quenched with ice water before analysis. The intermolecular hydride transfer between tertiary and secondary carbenium ions and alkanes is generally much faster than the alkylation reaction. Consequently, the alkylation products are also those derived from the new alkanes and carbenium ions formed in the hydride transfer reaction. 

Dialkylamino derivatives of elements located in the periodic table to the left or below those listed above cannot be prepared by the above method due to either the ionic character of some of the inorganic halides or the formation of stable metal halide-amine addition products. Therefore, other methods must be applied. Dialkylamino derivatives of tin and antimony are conveniently obtained by reaction of the corresponding halides with lithium dialkylamides. Others, such as the dialkylamino derivatives of aluminum, are made by the interaction of the hydride with dialkylamines. Dialkylamino derivatives of beryl-lium or lithium result from the reaction of the respective alkyl derivative with a dialkylamine. 

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