Mixed halides preparation

Tin(II) difluoride oxidatively adds X2 (X = C1, Br) in acetonitrile solution to form the mixed monomeric halide (MeCN)2SnF2Cl2 and oligomeric [(MeCN)2SnF2Br2] . For the reaction with I2, the product obtained is (MeCN)2SnF4, and as such represents a new and convenient route to the tetrafluoride, by the elimination of the solvent molecules. These may also be exchanged for a range of other ligands, and complexes with DMSO, DMF, THF, and pyridine were reported. In DMSO solution the same reactions lead to disproportionation products in preference to the mixed halides prepared in acetonitrile." ... 

The mixed halide-hydrides PhjSnHCl and PhjSnHBr have been prepared from the reaction of diphenyltin dihydride with the appropriate diphenyltin dihalides (274). 

Explosions sometimes resulted on opening sealed tubes in which complex mixed halide salts of this compound had been prepared. There is no obvious source of pressure in the reaction mixture of dipotassium tetradecachlorotungstate, lithium iodide and potassium iodide. 

When [AsCl4][AsF6] is pyrolyzed, the mixed halide AsC1F5 is formed in preparative quantities.75 IR studies indicate the chlorine to be in an equatorial position, as expected from its lower electronegativity. 

Infrared spectroscopy is not as inherently informative with regard to metal interactions in highly symmetrical metal-metal bound dimers as is Raman spectroscopy, since the totally symmetric metal-metal stretch is a forbidden absorption in the infrared experiment. Oldham and Ketteringham have prepared mixed-halide dimers of the type Re2ClxBr 2xto lower the symmetry and hence introduce some infrared allowedness into the Re-Re stretching mode (206). Indeed, the appearance of a medium-intensity band at 274 cm 1 in the infrared spectrum of the mixed-halo species was considered to be the result of absorption by the metal—metal stretching vibration, which was also observed in the Raman spectrum at 274 cm ". ... 

The reaction of bis[trifluoromethyl] tellurium with chlorine fluoride at — 78° with fluorotrichloromethane as solvent first produced his[trifluoromethyl] tellurium chloride fluoride. When the reaction mixture was concentrated, the l9F-NMR signal of the chloride fluoride disappeared and was replaced by signals for bis[trifluoromethyl] tellurium difluoride and bis[trifluoromethyl] tellurium dichloride2. The diorgano tellurium dihalides reported in the literature as mixed dihalides might be mixtures of symmetrical dihalides. All mixed halide species were identified by 125Te- and 19F-NMR spectroscopy in dimethylformamide solutions prepared from equimolar amounts of two different tellurium dihalides3. 

Several mixed halide compounds are known that have formulas such as PCI3F2, PF3C12, and PF3Br2. These compounds are prepared by adding a halogen to phosphorus trihalides that contain a different halogen, and a typical reaction is... 

A mixed halide compound can be prepared by means of the following reaction ... 

Many of the mixed halides CX4- X are also known.40 There are also derivatives with three halide atoms, e.g., CC1F2I or CBrF2I. However, the prototype of the chiral compounds, CBrCIFI, has not been prepared yet but CHBrCLF has. 

Most of the other products (16-22), can be made directly from (14) and aUcylammonium or phosphonium salts, R4EX (E = N, P), under appropriate thermal and stoichiometric conditions. Mixed-halide derivatives have also been made. The preparation of the derivatives of the [ReX(CO)3] fragment, (19), (20), (21), and the tetrahedrane (22), require higher temperatures. 

Polymeric species [(AgmX ) " " ]co (X = Cl, Br, I) have been identified in several crystal structures. Silver complexes with mixed halide ligands have also been prepared, for example, discrete [Ag2Br4Cl2] and polymeric [(Ag6X2l6)2-]oo (X = Cl, Br). ... 

The insertion method is preferred for preparing (a) [SnCl3] complexes of elements in normal valence states, (b) mixed-halide complexes, [SnX2Y] , and (c) complexes containing the Sn[CH(SiMe3)2]2X group. 

Halo nitriles are prepared from the corresponding dihalides or from mixed halides by taking advantage of the different reactivities of two dissimilar halogen atoms. ... 

Here, mixed cuprates prepared from organolithium or organomagnesium compounds serve as a carbanion, while derivatives like alkyl halides, alkyl sulfonates, or alkyl acetates are suitable equivalents for the carbocationic counterpart (Scheme 2.34). 

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