Group IVB Titanium

Very little is known about chalcogenide halides of Group IVB elements. Although the existence of sulfide chlorides (45, 274, 329, 365) and of a selenide chloride (329) of titanium was claimed in early publications, their true composition, and even their existence, remains doubtful. They have usually been obtained by the reaction of titanium chlorides with sulfur and selenium, respectively, or with hydrogen sulfide. The synthesis of a pure compound, TiSClj, was published in 1959 (113). It is an intermediate of the reaction of TiCU with HjS. 

Halogeno-telechelic polymers result from complete ionization of both ends of telechelic prepolymers. Teyssie et aL [38] developed a facile process of synthesizing dicarboxylato polymers based on Group IVb metal ions (Ti/Zr). Addition of a stoichiometric amount of tetra-n-butoxy-titanium Ti(0-nBu)4 to a carefully... 

In the lower oxidation states the chemistry of titanium has little or no counterpart in the chemistries of the group IVB elements. The only lower oxidation state of these elements is two, for which the stability order is Ge < Sn < Pb. However,, both zirconium(III) and hafnium(III) are similar to if less stable (towards oxidation) than titanium(III) and have comparable although less extensively investigated chemistries. 

Low valent species of transition metals (Groups IVB, VB and VIB) have found widespread use in the reduction of nitro compounds. Chromium(II) chloride, titanium(III) chloride and vanadium(II) sulfate readily reduce aromatic nitro compounds to arylamines. Chromium(II) chloride also reduces nitrobenzene and nitroquinoline to the corresponding amines in excellent yields. ... 

New porphyrin-containing Group IVB polymers were made using ricinoleic acid215 or hematoporphine IX.210,217,218 Polymer 93 is a representative example that was used as a selective chelating agent. Macrocyclic tetrapyrrole has four methyl, two ethanolic, and two propionic acid side chains. The polymers are cross-linked because of the four reactive functions (two acid and two alcohol groups). The adsorption of Ni+2 by porphyrin moieties was observed for the titanium polymer. 

The only known azide in the group IVB is titanium(IV) azide trichloride, Ti(N3)Cl3. As a typical mixed azide, the yellow, covalent compound is hygro-... 

A variety of other ternary and quaternary carbides and carhonitrides is especially interesting for use in metal cutting tools in the form of layers, and powder particles have been investigated recently for their specific heat, temperature and thermal conductivity [66]. The behavior of the heat conductivity of most of these compounds is similar to that of the group IVB carhonitrides for (near) stoichiometric composition showing a positive curvature of heat conductivity as a function of temperature. Interestingly, however, Nb- and Mo-containing ternary titanium carbides and nitrides and quaternary titanium carhonitrides show a hnear behavior in the same temperature interval. 

The cyclopentadienyl derivatives of titanium, zirconium, and hafnium were first described by Wilkinson and coworkers in the early 1950s. These compounds have a tetrahedral geometry, possess a high degree of covalent character and behave like organic acid chlorides in condensation polymerization reactions. Group IVB metallocene-containing materials are known to be active catalytic sites and to offer potentially useful photonic and other properties. ... 

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