Rhenium tetrachloride

Rhenium tetrachloride oxide, 4167 Rhodium(III) chloride, 4155 Rhodium tetrafluoride, 4349 Ruthenium(III) chloride, 4156 Silver chloride, 0008... 

Rhenium tetrachloride oxide, 4167 Ruthenium(VIII) oxide, 4862... 

Nonachlorotrirhenium(III) is a dark red crystalline solid. When heated strongly it gives a green vapor. It is reduced by hydrogen to the metal at 250-300°C. and reacts with oxygen to yield perrhenyl chloride and rhenium oxide tetrachloride.4... 

Derivation By reacting rhenium heptoxide with carbon tetrachloride at 400C. 

In a similar manner, (acetonitrile)trichlorobis(triphenylphosphane)rhenium(lll), as well as dichlorotris(triphenylphosphane)ruthenium(II), catalyze the addition of carbon tetrachloride and bromotrichloromethane to 1,6-dienes to give 1.2-disubstituted cyclopentanes or analogous heterocycles. The cyclization products, obtained in good yield, show preferred cis geometry of the neighboring substituents33. The reactions are interpreted to proceed via a radical mechanism with the metal acting as simple initiator. 

The formation of the hydrides may proceed via bis(jr-cyclopentadienyl)-metal halide complexes, since compounds such as (ir-CeH ReCU+CI-and (t-CjHOjWCU are known and are readily reduced to the neutral hydrides on treatment with lithium aluminum hydride 64) (Eq. 5). Treatment of technetium tetrachloride with sodium cyclopentadiene does not give a hydride analogous to that of rhenium. Molecular weight determina-... 

Microgram amounts of TcOj can be ascertained by measuring the absorbance of the colored complex, formed with toluene-3,4-dithiol in 2.1 M HCl, after extraction into carbon tetrachloride. One hour must be allowed for the development of the color. ITie molar absorbance index at 410 nm is 1.1-10" mole -1-cm. Beer s law is followed over the range of 1.1 to 16.1 pg Tc/ml. Because many cations interfere, an initial separation of technetium is necessary [73]. The same complex was used for the determination of technetium in uranium fission element alloys after separation of Tc by distillation from sulphuric acid [74j. I hc complex formation of technetium, rhenium, and molybdenum with toluene-3,4-dithiol and its analytical application have been studied in detail [71]. 

The hard black rhenium (IV) iodide is transferred to a test tube 30 cm. long and 25 mm. o.d., which has been constricted to about 10-mm. i.d. at the center. Five grams of iodine is placed on the tetraiodide and the tube is evacuated (oil-pump) and sealed. The tube is heated at 350 5° for 8 hours in a furnace. The tube is then adjusted in such a manner that the rhenium(III) iodide which has formed is maintained in one portion in the furnace at 220° while the other portion protrudes from the furnace. The latter portion is allowed to cool slowly at first and is then cooled further by a jet of air. When all the iodine has apparently collected in the cooled portion, the entire tube is allowed to cool to room temperature. The tube is then scored in the center with a file and broken. (Care is taken to effect a break without introducing shards of glass into the product.) The glistening black crystals are transferred onto the fritted-glass plate of a tared crucible and washed with carbon tetrachloride until the washings are colorless. (About 400 ml. of solvent is required.) The product is then rinsed with two 20-ml. portions each of ethanol and ethyl ether and dried at 110°. The yield is 16.3 g. or 83%. Anal. Calcd. for Reis Re, 32.8 1, 67.2. Found Re, 33.0 1,67.0. 

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