Titanium, tris structure

Titanium, tetrakis(trimethysilyl)oxy-, 3, 334 Titanium, tetranitrato-stereochemistry, 1,94 Titanium, triaquabis(oxalato)-structure, I, 78 Titanium, tris(acetylacetone)-structurc, 1,65 Titanium alkoxides oligomeric structure, 2,346 synthesis ammonia, 2, 338 Titanium chloride photographic developer, 6,99 Titanium complexes acetylacetone dinuclear, 2, 372 alkyl... 

Fig. 5.21. Top Self-assembly drives the formation of helical, homochiral dimeric titanium tris-catecholate complexes. Dimerization is only mediated by LC, while Na and K" " do not lead to comparable products. Bottom Crystal structures of the dimers formed from the aldehyde (left, R = H), the ethyl ketone (centre, R = C2H5), and the methyl ester (right, R = OCH3). Shown is a side view in space-filling representation and a ball-and-stick model with a view along the Ti—Ti...

Titanium, tris(acetylacetone)-structure, 65 Titanium(III) complexes magnetic behavior, 271 spectra, 250 Titanium tetrachloride photoreactivity, 406 Titrimetry, 552 T oluene-3,4-dithiol in gravimetry, 534 metal complexes liquid-liquid extraction, 547 Topochemical reactions, 463 Topotactic reactions, 463 Trans effect, 16, 26,315 six-coordinate compounds, 49 Trans influence square planar complexes, 38 Transition metal complexes d... 

The physical and chemical properties of the tetrahydroborates show more contrasts than the salts of nearly any other anion. The alkali metal salts are the most stable. In dry air, NaBH4 is stable at 300°C and in vacuo to 400°C with only partial decomposition. In contrast, several tetrahydroborates, including the titanium, thallium, gallium, copper, and silver salts, are unstable at or slightly above ambient temperatures. The chemical and physical properties of the tetrahydroborates are closely related to molecular structure. Sodium tetrahydroborate, which is typical of the alkali metal tetrahydroborates except for the lithium salt, has a face-centered cubic (fee) crystal lattice which is essentially ionic and contains the tetrahedral [BHJ- anion. The tetrahydroborates of the polyvalent metals are in many cases the most volatile derivatives of these metals known. Aluminum tris(tetrahydroborate)... 

Figure 8.17 (a) The Ti02(l 10) surface with surface Tie, and Tise atoms. Titanium, silver oxygen, red other atoms in the slab, green, (b) The relaxed structure of the three tri-layer slab viewed in cross-section, (c) The relaxed structure of the four tri-layer slab. Atom colors for the surface layer of (a) are used throughout (b) and (c). 

The elucidation of structural details for four titanium alkoxides, Ti(OR)4 (where OR = O-r-Am, O-r -Pr, OEt, and O-n-Bu) may be cited as a practical illustration (189) of the application of these techniques. Both Ti(0-r-Am)4 and Ti(0-i -Pr)4 were shown to be tetrahedral monomeric molecules, whereas Ti(OEt)4 and Ti(0- -Bu)4 were shown to be oligomers (probably tri-meric, n = 3) with the Ti—O bond distances of 1.80 (terminal) and 2.05 A (bridging), as well as Ti—Ti interactions (observed for the first time) of 3.1 A. Based on the information available from XANES studies, the most probable coordination number of titanium is 5 in a threefold oligomer. 

The applications of these ligands have been limited to the work by Nakazawa et al.244 who found tris(pyrazolyl)methane titanium complexes to be high-activity catalysts for the polymerization of olefins, and the use of tris(pyrazolyl)methane zinc complexes to model zinc-containing enzymes, such as dihydrorootase and carbonic anhydrase.245 The structure of the free ligand HC(Me2pz)3 has also been reported.246... 

In contrast to main-group elements, transition metals usually try to reach high coordination numbers. Therefore, the 1,2-azaborolyl rings are normally t -coordinated, offering 6jt-electrons to the metal, if it is considered formally as an anion, except to the late and electron-rich representatives. Titanium and vanadium each form bent-type complexes as a result of the presence of two chloro ligands and one chloro ligand, respectively. Figures 13 and 14 show the structures. 

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