Titanium complex compounds

Titanium cesium alum, 6 50 Titanium (II) chloride from disproportionation of titanium (III) chloride, 6 56, 61 Titanium(III) chloride, 6 52, 57 Titanium (IV) chloride, reduction of, with hydrogen, 6 52, 57 Titanium complex compounds, cations, with acetylacetone, [Ti-(C.H. hTiCl, and [Ti(C6H7-0,),]FeCl , 2 119, 120 Titanium(IV) oxide, extraction of, from ilmenite, 5 79, 81 to titanium powder with calcium, 6 47... 

Tinphosphorus compounds, organo- 13, 179 Tin salts, removal 15, 322 Tishler condensation 4, 418 Titanium complex compounds, ar. 15, 506... 

Peroxidic Compounds. When hydrogen peroxide is added to a solution of titanium(IV) compounds, an intense, stable, yellow solution is obtained, which forms the basis of a sensitive method for determining small amounts of titanium. The color probably results from the peroxo complex [Ti(02)(0H)(H20)J, and crystalline salts such as K2[Ti(02)(S0 2] H20 can be isolated from alkaline solutions. The peroxo ligand is bidentate the two oxygen atoms ate equidistant from the titanium (98). 

The intense reddish-brown color of the acetylacetone titanium complexes impart a yellow discoloration to white inks. This discoloration is accentuated when the inks are used to print substrates that contain phenol-based antioxidants. The phenoHc compounds react with the organic titanate to form a highly colored titanium phenolate. Replacement of 0.25 to 0.75 moles of acetylacetone with a malonic acid dialkyl ester, such as diethyl malonate, gives a titanium complex that maintains the performance advantages of the acetyl acetone titanium complexes, but which is only slightly yellow in color (505). These complexes still form highly colored titanium phenolates. 

A new process developed by Institut Francais du Petrole produces butene-1 (1-butene) by dimerizing ethylene.A homogeneous catalyst system based on a titanium complex is used. The reaction is a concerted coupling of two molecules on a titanium atom, affording a titanium (IV) cyclic compound, which then decomposes to butene-1 by an intramolecular (3-hydrogen transfer reaction. ... 

A synthetically useful diastereoselectivity (90% dc) was observed with the addition of methyl-magnesium bromide to a-epoxy aldehyde 25 in the presence of titanium(IV) chloride60. After treatment of the crude product with sodium hydride, the yy -epoxy alcohol 26 was obtained in 40% yield. The yyn-product corresponds to a chelation-controlled attack of 25 by the nucleophile. Isolation of compound 28, however, reveals that the addition reaction proceeds via a regioselective ring-opening of the epoxide, which affords the titanium-complexed chloro-hydrin 27. Chelation-controlled attack of 27 by the nucleophile leads to the -syn-diastereomer 28, which is converted to the epoxy alcohol 26 by treatment with sodium hydride. 

Several aluminum- and titanium-based compounds have been supported on silica and alumina [53]. Although silica and alumina themselves catalyze cycloaddition reactions, their catalytic activity is greatly increased when they complex a Lewis acid. Some of these catalysts are among the most active described to date for heterogeneous catalysis of the Diels-Alder reactions of carbonyl-containing dienophiles. The Si02-Et2AlCl catalyst is the most efficient and can be... 

The discussion above might have pertained for example, to the energies and electronic spectra of titanium(iii) compounds. The same ideas can be applied with just one modification to the i/-electron properties of copper(ii) complexes and other... 

The layer of titanium and ruthenium oxides usually is applied to a titanium substrate pyrolytically, by thermal decomposition (at a temperature of about 450°C) of an aqueous or alcoholic solution of the chlorides or of complex compounds of titanium and rathenium. The optimum layer composition corresponds to 25 to 30 atom % of ruthenium. The layer contains some quantity of chlorine its composition can be written as Ruq 2sTio 750(2- c)Cl r At this deposition temperature and Ru-Ti ratio, the layer is a poorly ordered solid solution of the dioxides of ruthenium and titanium. Chlorine is completely eliminated from the layer when this is formed at higher temperatures (up to 800°C), and the solid solution decomposes into two independent phases of titanium dioxide and ruthenium dioxide no longer exhibiting the unique catalytic properties. 

Some of the vinyl monomers polymerized by transition metal benzyl compounds are listed in Table IX. In this table R represents the rate of polymerization in moles per liter per second M sec-1), [M]0 the initial monomer concentration in moles per liter (M) and [C]0 the initial concentration of catalyst in the same units. The ratio i2/[M]0[C]0 gives a measure of the reactivity of the system which is approximately independent of the concentration of catalyst and monomer. It will be observed that the substitution in the benzyl group is able to affect the polymerization rate significantly, but the groups that increase the polymerization rate toward ethylene have the opposite effect where styrene is concerned. It would also appear that titanium complexes are more active than zirconium. The results with styrene and p-bromostyrene suggests that substituents in the monomer, which increase the electronegative character of the double bond, reduces the polymerization rate. The order of reactivity of various olefinically unsaturated compounds is approximately as follows ... 

Polysulfides of several metals can be prepared by reaction of the metals with excess sulfur in liquid NH3 (group IA metals) or by heating sulfur with the molten metal sulfide. The polysulfide ion binds to metals to form coordination compounds in which it is attached to the metal by both sulfur atoms (as a so-called bidentate ligand). One example is an unusual titanium complex containing the S52-ion that is produced by the following reaction (the use of h to denote the bonding mode of the cyclo-pentadienyl ion is explained in Chapter 16) ... 

Addition of the (l-silylalkyne)titanium complex to carbonyl compounds and imines occurs at the (3-position to the silyl group, as shown in Fig. 9.2. However, the reaction with sBuOH takes place exclusively at the carbon—titanium bond a to the silyl group to give the (P-silylalkenyl)titanium species, as in Eq. 9.5 (values in square brackets denote the regioselectivity) [24], where the vinyl—titanium bond is visualized by the outcome of the iodi-nolysis. The overall reaction can therefore be regarded as the hydrotitanation of silylace-... 

The phosphino-oxazoline copper(II) complex (55) has also been found to be an effective catalyst[136] as have some titanium complexes, such as the extensively researched titanium-TADDOL system (56)[137]. A modified Ti(IV)-TADDOL compound is the catalyst of choice to promote Diels-Alder cycloaddition reactions between cyclopentadiene and alk-2-enyl phenylsulfonylmethyl ketones[138]. 

Titanium(IV) complexes, 25 97-101 Titanium(IV) compounds six-coordinated, 25 90 Titanium(IV) cyclopentadienyls, 25 110, 111—112t... 

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