Reducing agents titanium compounds

Manufacture. Titanium chloride is manufactured by the chlorination of titanium compounds (1,134—138). The feedstocks usually used are mineral or synthetic mtile, beneficiated ilmenite, and leucoxenes. Because these are all oxygen-containing, it is necessary to add carbon as well as coke from either coal or fuel oil during chlorination to act as a reducing agent. The reaction is normally carried out as a continuous process in a fluid-bed reactor (139). The bed consists of a mixture of the feedstock and coke. These are fluidized by a stream of chlorine iatroduced at the base (see Fluidization). The amount of heat generated in the chlorination process depends on the relative proportions of CO2 or CO that are formed (eqs. 1 and 2), and the mechanism that... 

A group of violet titanium(III) acylates has been prepared from TiCl and alkafl carboxylates. AH of the acylates are strong reducing agents similar to TiCl (189). Studies of Ti(III) compounds include the reaction (190)... 

Polymers containing 90-98% of a c 5-1,4-structure can be produced using Ziegler-Natta catalyst systems based on titanium, cobalt or nickel compounds in conjuction with reducing agents such as aluminium alkyls or alkyl halides. Useful rubbers may also be obtained by using lithium alkyl catalysts but in which the cis content is as low as 44%. 

The Nef reaction can also be carried out with reducing agents. Aqueous titanium chloride reduces nitro compounds to imines, which are readily hydrolyzed to carbonyl compounds (Eq. 6.17).28 The Michael addition of nitroalkanes to enones followed by reaction with TiCl3 provides an excellent route to 1,4-diketones and hence to cyclopentenones. For example, cw-jasmone is readily obtained,28 as shown in Eq. 6.18. 

Titanium nitride films have usually been prepared by OMCVD from dialkylamido titanium compounds Ti(NR2)4 and ammonia, which plays a major role in the process as a reducing agent and source of nitrogen.12,13 Other authors have reported the use of azide compounds such as Cp2Ti(N3)2 or [Ti(NMe2)(N3)(p-NMe2)]3(p3-NH), with the former compound,14 contamination of the films by free carbon from the decomposition of the Cp group is mentioned, while with the latter,15 which occurs as a trimeric species, a lack of sufficient volatility rules out its use as a CVD precursor. 

Thorium oxybromide, 1 54 Tin, as reducing agent for complex tungsten(VI) chlorides in preparation of complex potassium chlorotungstates(III), 6 149 Tin compounds, halomethyl derivatives, by the diazomethane method, 6 37 (CH8) 2 (CH2C1) SnCl, 6 41 Tin (IV) iodide, 4 119 Titanium, powder by reduction of titanium (IV) oxide with calcium, 6 47... 

Titanium(II) compounds are very strong reducing agents many react with various small molecules. In the presence of N2, /rans-[TiCl2(TMEDA)2] reacts with the sterically demanding lithium amide LiN(SiMe3)2, in pyridine, to give 17-A-X and similar complexes 78 these N2 complexes contain very short (ca. 1.7 A) Ti=N bonds and are best considered as TP compounds. 

McMurry developed a reduction procedure that is used for alkenation of carbonyl compounds in the presence of low-valent titanium (LVT) reagent. The reagent (thought to be a mixture of Ti(0) and Ti(II) species) is formed by the reduction of TiCU or TiCb with a suitable reducing agent (Zn-Cu alloy, LiAlH4 or alkali metal are the most commonly used). 

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