Thallium complexes ethers

Method A A solution of 0.5 mmol of (2/ /S ,3R/S )-2,3-dialkyl-1,4-diarylbutane and 0.125 mL (1.0 mmol) of boron trifluoride-diethyl ether complex in 2 mL of trifluoroacctic acid is added to a suspension of 0.12 g (0.26 mmol) of thallium(III) oxide in 2 mL of trifluoroacetic acid at — 40°C to +25CC under an argon atmosphere. The dark colored solution is stirred until the reaction is complete, diluted with ethyl acetate, then washed successively with water (twice) and sat. aq NaCl. Evaporation of the dried extract gives the crude product. In a variant of this method the boron trifluoride-diethyl ether complex can be omitted. 

The mixture is stirred for 45 min at room temperature, and subsequently for 2 h at 80 °C. The precipitated thallium(I) chloride is filtered and the filtrate is evaporated to dryness. The white residue is extracted with 30 mL of diethyl ether, concentrated to 8 mL and addition of 30 mL of hexane causes precipitation of the white title complex. Yield 1.29 g (82%). 

G. Canneri found that the treatment of a suspension of thallium sesquioxide in water with liquid nitrous anhydride, and subsequent evaporation of the soln., even in the cold under reduced press., yields, not thallic nitrite, but thallous nitrate. The latter is also obtained when soln. of thallic sulphate and barium nitrite are mixed in the cold, and the resulting liquid evaporated at low temp. That thallic nitrite is capable of existence in soln., although it cannot be obtained in the solid condition, is shown by the analyses and properties of the soln. The treatment of an aq. soln. of thallic nitrite with alcohol yields a precipitate of the sequioxide. In ethereal soln., thallic nitrite is far more stable, and the salt separates in the solid state on evaporation of the solvent it could not, however, be analyzed directly. Decomposition of thallic nitrite, with formation of thallous nitrate, takes place solely in accordance with the equation T1 (N02)3->TlN03+N2Os, neither intermediate reduction products nor thallous-thallic complex compounds being formed. 

Of the thallium halide complexes, the bromide complex is the most important in extraction separations. Tl(III) and Au(IlI) are extracted quantitatively from 1-3 M HBr with diethyl ether or DIPE, or MIBK. At that concentration of HBr, Fe(lII), Ga, In, Hg, and Te are extracted in small amounts. After extraction with MIBK, Ga, In, Fe(IlI), and Sn are stripped with a 1.5 iW HBr formamide solution, leaving only Tl(III) in the ketone phase [1]. The thallium(III) bromide eomplex has been extracted with TO A in benzene [2], or n-octylaniline in CHCI3 [3],... 

Extraction of the chloride complex of thallium(III) from HCl media is less selective [4-6]. For diethyl ether and DIPE, the most suitable media are 4 M HCl and 6 M HCl, respectively. Au(III), Fe(III), Sb(V), Sn, Hg, Mo, As, Ge, and Ga are partly extracted along with the thallium(III) from an HCl medium. Extraction of Tl(lII) from less concentrated HCl media by using CHCI3 solutions of n-octylaniline has been proposed [7]. 

From the dithizone-CHCfi medium T1 is stripped with dilute HNO3, or the solvent is volatilized, and dithizone mineralized with a mixture of H2SO4 and HNO3. Sometimes, thallium is separated before the determination, as the bromide complex, by extraction with diethyl ether. 

Aluminium and Thallium. - A new synthesis of triethylaluminium (as its diethyl etherate complex) has been achieved by ultrasonic irradiation... 

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