Titanium metal potassium

Perhaps because of inadequate or non-existent back-bonding (p. 923), the only neutral, binary carbonyl so far reported is Ti(CO)g which has been produced by condensation of titanium metal vapour with CO in a matrix of inert gases at 10-15 K, and identified spectroscopically. By contrast, if MCI4 (M = Ti, Zr) in dimethoxy-ethane is reduced with potassium naphthalenide in the presence of a crown ether (to complex the K+) under an atmosphere of CO, [M(CO)g] salts are produced. These not only involve the metals in the exceptionally low formal oxidation state of —2 but are thermally stable up to 200 and 130°C respectively. However, the majority of their carbonyl compounds are stabilized by n-bonded ligands, usually cyclopentadienyl, as in [M(/j5-C5H5)2(CO)2] (Fig. 21.8). 

Titan-kaliumfluorid, n. potassium fluotitanate, -karbid, n, titanium carbide, -metall, n. titanium metal, -nitrid, n, titanium nitride, TitanofluorwasserstoffsMure, /. fluotitanous acid, fluotitanic(III) acid,... 

For preparative purposes, titanium metal can be used in place of sodium or lithium in liquid ammonia for both the vinyl phosphate231 and aryl phosphate232 cleavages. The titanium metal is generated in situ from TiCl3 by reduction with potassium metal in tetrahydrofuran. 

Titanium metal also can be produced by electrolytic methods. In electrolysis, fused mixtures of titanium tetrachloride or lower chlorides with alkaline earth metal chlorides are electrolyzed to produce metal. Also, pure titanium can be prepared from electrolysis of titanium dioxide in a fused bath of calcium-, magnesium- or alkali metal fluorides. Other alkali or alkaline metal salts can be substituted for halides in these fused baths. Other titanium com-pouds that have been employed successfully in electrolytic titanium production include sodium fluotitanate and potassium fluotitanate. 

Merthyr Tydvil, but F. Wohler (18) showed in 1849 that these were not the metal itself but a mixture of the nitride and cyanide. In 1825 Berzelius (20) prepared some very impure amorphous titanium by reducing potassium fluotitanate, K2TiF6, with potassium. Although the resulting black powder gave a metallic streak, it was insoluble in hydrofluoric acid and therefore could not have contained much titanium metal (23). 

Methylenation of ketones.3 A new method for this reaction is outlined in the example. The titanium metal used for the second step is prepared by treatment of TiCl j with potassium in refluxing THF. 

Titanium tetrachloride is used as an intermediate in the production of titanium metal, titanium dioxide, and titanium chloride pigments, as a polymerization catalyst, in the manufacture of iridescent glass and faux pearls, and with ammonia to produce smoke screens. It is also used as a catalyst in many organic syntheses in the chemical industry. Titanium tetrachloride was formerly used with potassium bitartrate as a mordant in the textile industry, and with dye-woods in dyeing leather. 

Alkenes can be obtained from aldehydes or ketones on reductive dimerization by treatment with a reagent prepared from titanium(III) chloride and zinc-copper couple (or L1A1H4), or with a species of active titanium metal formed by reduction of titanium(III) chloride with potassium or lithium metal. This McMurry coupling reaction is of wide application, but in intermolecular reactions generally affords a mixture of the E- and Z-alkenes (2.99). 

An active titanium metal can be prepared by reaction of TiCIa slurried in THF or DME with potassium or lithium (method of Rieke, 4, 315). 

The reaction takes place on reduction of chlorides of titanium in oxidation state (m) or (iv) by metallic potassium or alkyl-lithium with subsequent decomposition of the organo-titanium species on warming. Titanium metal alkoxide radical anion systems have also been shown to act as catalysts in the conversion of elemental nitrogen to hydrazine ... 

Klaproth and many contemporary chemists tried in vain to isolate titanium metal, but in 1825 Berzelius succeeded in reducing potassium hexafluorotitanate K TiF with metallic potassium. The titanium metal obtained, however, was very impure. The same method was used two decades later by Friedrich Wohler and Sainte-Claire Deville. They got a powder with a metallic luster and thought at first that their prepa-rahon was pure titanium metal, until they found that the reaction product was rich in nitrides. Welders of htanium components today recognize the situation. Even under a protective atmosphere of argon or helium, the slightest traces of nitrogen lead to the formahon of yellow titanium nitride. 

Class D extinguisher. For use on combustible metals such as magnesium, titanium, sodium, potassium, and zirconium. 

Titanium metal generated by stronger reducing agents, such as Li AIH4 or lithium or potassium metal, effects complete removal of oxygen with formation of alkene. ... 

Chinuka An electrochemical process for making titanium metal directly from a titaniferous raw material such as rutile. The rutile is mixed with carbon and heated to above 1400°C in a vacuum, producing titanium oxycar-bide. This is electrorefined using a molten sodium/potassium chloride eutectic as the electrolyte. Developed by D. Fray and S. Jiao in Cambridge, United Kingdom. Licensed to White Mountain Titanium Corp, Chinuka... 

Nitric acid reacts with all metals except gold, iridium, platinum, rhodium, tantalum, titanium, and certain alloys. It reacts violentiy with sodium and potassium to produce nitrogen. Most metals are converted iato nitrates arsenic, antimony, and tin form oxides. Chrome, iron, and aluminum readily dissolve ia dilute nitric acid but with concentrated acid form a metal oxide layer that passivates the metal, ie, prevents further reaction. 

Sodium ethoxide was the first metal alkoxide described in 1837 (1). The alkoxides of many transition metals were developed after World War II (2—5). Today some alkoxides, including those of sodium, potassium, magnesium, aluminum, zirconium, and titanium, are commercially important. The name metal alkoxides is preferred, although metal alcoholates is also used. 

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