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Fluorocarbon derivatives of arsenic, sulfur and nitrogen.

University of British Columbia

The disulfides RSSR (R = C₂H₅,C₆H₅ and CF₃ ) read with the diarsines R₂' As-AsR'₂ (R' = CH₃, CF₃) to give the compounds R'₂ As-SR. Dimethylarsine readily cleaves As-S and As-N bonds to yield a diarsine and the corresponding thiol and amine respectively. Unsymmetrical disulfides are obtained from the reaction of trifluoromethanesulfenyl-chloride with compounds containing arsenic-sulfur bonds. Trifluoromethanesulfenylchloride is readily reduced by dimethylarsine to yield chlorodimethylarsine and trifluo-romethanethio1. Tetramethyldiarsine is readily cleaved by trifluoromethanesulfenylchloride and trifluoromethanesulfonylchloride and yields trifluoromethyIthiodimethy-larsine and trifluoromethanesulfonyldimethylarsine respectively, in addition to chlorodimethylarsine, Tetramethyldiarsine also reacts with methanesulfonylanhydride to yield dimethylarsinomethanesulfonate. The cyclic f luoro-olefins RC= CR'CF₂(CF₂)n (n = 1, R = R' = F, R = R' = Cl, R = Cl, R' = H, and n = 2, R = R' = Cl, R = Cl, R' = H) react with secondary amines and arsines to give the compounds R"C= CR'CF₂ (CF₂) (R" = (C₂H₅ )₂N, (CH₃)₂ As), Methane thiol also reacts with these cyclic fluoroolefins (n = 1, R = R' = F, R = R'=Cl) to yield the compounds CH₃SC = CR'CF₂CF₂(R' = F, Cl). With 1-H-2-chlorotetrafluorocyciobutene, methane thiol affords a 1:1 adduct, which fails to eliminate hydrogen halide even at 150. With 1-H-2-chlorohexafluorocyclopentene and methane thiol, double bond migration occurs to yield 1-chloro-5-H-5-methylthiopentafluoroeyelopentene, 1-Ethyl-2-chiorotetrafluorocyciobutene affords 1-ethyl-2-methylthiotetrafluorocyciobutene and 1-ethyl-2-dimethyl-arsinotetrafluorocyciobutene when heated with methane thiol and dimethylarsine respectively. The rates of the above reactions are dependent on the nucleophilicity of the attacking nucleophile, the size of the fluoro-olefin ring and the electronegativity of the groups attached to the double bond. The chelating properties of the new ditertiary arsine, 1,2-dimethylarsinotetrafluorocyclobutene (difars) have also been investigated. Reaction with Fe(CO)₅ and Mo(CO)₆ under mild conditions yields the stable crystalline complexes [(difars) Fe(CO)₃] and[(difars) Mo(CO)₄], and under vigorous conditions all the carbon monoxide can be displaced from Mo(CO)₆. Difars displaces all the carbon monoxide from Ni(CO)₄ at 25°, but attempts to obtain coordination complexes of difars with Ni(II) salts have been unsuccessful. Platinum and palladium salts react with difars to yield stable crystalline complexes which can be formulated as [(difars) PtCl ₂]and [(difars) PdCl₂]. Rhodium trichloride trihydrate affords the complex [Rh (difars)₂Cl₂]Cl. Mercuric chloride and cadmium bromide yield the unstable complexes [(difars) HgCl₂] and [(difars)CdBr₂]

Text

2011-08-22

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http://hdl.handle.net/2429/36805

Chemistry

University of British Columbia

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