Hydrides lanthanoid

The typical structure for the composition MH2 is a cubic closest-packing of metal atoms in which all tetrahedral interstices are occupied by H atoms this is the CaF2 type. The surplus hydrogen in the lanthanoid hydrides MH2 to MH3 is placed in the octahedral interstices (Li3Bi type for LaH3 to NdH3, cf. Fig. 15.3, p. 161). 

Activation of the C-O bonds in vinyl ethers promoted by a lanthanoid hydride has been reported (Eq.41) [85]. 

Examples of processes involving a-bond metathesis are recently increasing [119]. Hydroboration of terminal olefins is catalyzed by lanthanoid hydride or... 

Magnetic Order/Disorder in Category (ii) Lanthanoid Hydride Halides... 

Among the reactions catalyzed by lanthanoid hydride species, besides the polymerization of olefins, the cyclization of unsaturated amines [66] and the reduction of organohalides RX to the corresponding hydrocarbons RH may be noted [67]. 

Table V.2. Vibration frequencies of Ln-H bonds in the lanthanoid hydrides.

Hydrogen can be prepared by the reaction of water or dilute acids on electropositive metals such as the alkali metals, alkaline earth metals, the metals of Groups 3, 4 and the lanthanoids. The reaction can be explosively violent. Convenient laboratory methods employ sodium amalgam or calcium with water, or zinc with hydrochloric acid. The reaction of aluminium or ferrosilicon with aqueous sodium hydroxide has also been used. For small-scale preparations the hydrolysis of metal hydrides is convenient, and this generates twice the amount of hydrogen as contained in the hydride, e.g. ... 

Hydrogen combines with many elements to form binary hydrides MH (or M H ). All the main-group elements except the noble gases and perhaps indium and thallium form hydrides, as do all the lanthanoids and actinoids that have been studied. Hydrides are also formed by the more electropositive transition elements, notably Sc, Y, La, Ac Ti, Zr, Hf and to a lesser... 

Numerous compounds adopt the PbFCl structure. These include, apart from fluoride chlorides, oxide halides MOX (M = Bi, lanthanoids, actinoids X = Cl, Br, I), hydride halides like CaHCl and many compounds with metallic properties like ZrSiS or NbSiAs. 

Fukuzawa, S., Fujinami, T., Yamauchi, S., Sakai, S. 1,2-Regioselective reduction of a,P-unsaturated carbonyl compounds with lithium aluminum hydride in the presence of lanthanoid salts. J. Chem. Soc., Perkin Trans. 11986, 1929-1932. 

The demand for the lanthanoid metals is expected to increase with the growing demands for pollution control catalysts in motor vehicles and rechargeable batteries. Along with lithium-ion batteries, nickel-metal hydride (NiMH) batteries find increasing applications in mobile phones, laptop computers and other portable electronic devices such as MP3 players. 

Organolanthanoide hydrides were prepared first in 1981/82 by the hydro-genolysis of alkyl(dicyclopentadienyl)lanthanoide derivatives (U7,139) ... 

Organolanthanoide hydrides (1 11,1 8,215,221), cyclopentadienyl-ytterbium(ll) complexes (190) as well as the cocondensation products of lanthanoides with acetylenic derivatives (137,216,222) catalyze the hydrogenation of olefins and acetylenes. 

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