Titanium hydride TiH

Titanium Hydride. TiH mw 49.92 blk metallic powdr, stable in air mp 400° (decompn evolves H2 initially above 288° and is practically complete at 650°) d 3.76g/cc. CA Registry No (7704-98-5]. Prepn is by a) direct combination of Ti with Hj or b) redn of TiOj with Ca hydride in the presence of H2 above 600°. The hydride may expld in the presence of oxidizu agents. However, EUern (Ref 1, p 252 and Ref 2, p 333) considers the hydride safer to handle than Ti, reporting that dry shipment is possible,... 

The in situ formed basic cyclopentadienyl complex of titanium, ethylene-bis( f-tetrahydroindenyl)-titanium hydride (EBTHI)TiH) containing a planar element of chirality, is active for the reduction of a C=N double bond of both N-aryl-imines (Schiff bases) and unsubstituted imines (108,109). (EBTHl)TiX2 derivatives are used as precursors of the hydride analogue. The chiral zirconium analogues of the above-mentioned complexes provided a breakthrough in asymmetric polymerization of terminal oleflns (110). 

Molecular hydrogen forms a number of hydrides with transition metals. In some of these compounds, the ratio of hydrogen atoms to metal atoms is not a constant. Such compounds are called interstitial hydrides. Depending on conditions, for example, the formula for titanium hydride can vaiy between TiH] s and TiH2. 

Reactivity of Cp TiH. The hydride Cp TiH is very air-sensitive, and reacts with moist air to give H2 and unidentified titanium containing compounds. With HCl it reacts at -80°C as expected (9). 

Hydride-dehydride process (HDH) Ti(s)-HH,(g)->TiH,(s) TiH,(s)->Ti(s)-m,(g) Hydriding of titanium followed by crushing and dehydriding at 700 C under reduced pressure Oremet, HC Starck, Kennametal, Sumitomo, Toho 90 Angular Oxide free, chlorine less than 10... 

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