Zirconium Dihydride Research Articles

A photoelectron spectroscopic study of the zirconium monohalide hydrides and zirconium dihydride. Classification of metal hydrides as conventional compounds

Etude d'halohydrures de Zirconium a partir de spectres photoelectron RX et UV; les etats des liaisons et leur distribution d'energie sont analyses, ainsi que la chimie a l'etat solide des hydrures metalliques et leurs relations avec les autres classes de composes metalliques

Reaction of [η 5-C 5H 5) 2ZrH(μ-H)] 2 with diphenylacetylene: mechanistic and theoretical considerations

The polymeric (Cp 2ZrH 2) x molecule is shown by 1H NMR studies to adopt a dimeric structure with bridging and terminal hydride ligands in both benzene- d 6 and toluene- d 8 solution. The reaction of the zirconium dihydride with diphenylacetylene has been re-investigated and produces a zirconacyclopentadiene complex 7, contrary to literature suggestions of a dimetallic zirconabenzene structure. A qualitative molecular orbital analysis of the [Cp 2ZrH(μ-H)] 2 dimer lends support to a suggested mechanism involving reaction with diphenylacetylene via a dimeric species.

The PMR spectrum of bis(π-tetrahydroindenyl)zirconium dihydride dimer: A new compound with an unusually low field hydrido resonance

The title compound has two magnetically distinct pairs of hydrido groups; one gives rise to a 1H NMR signal at δ–1.56 (i.e. upfield from TMS), whereas the other is downfield at δ 4.59.

Some physical properties of titanium and zirconium dihydrides

Some physical properties of titanium and zirconium dihydrides

Lattice-parameter changes in the pseudo-binary system of titanium and zirconium dihydride

Lattice-parameter changes in the pseudo-binary system of titanium and zirconium dihydride

Phase transformation, twinning and anelastic phenomenon associated with zirconium dihydride

The atom movements and crystallography of cubic to tetragonal transformation in ZrH 2 are studied and discussed according to the phenomenological theories of Bowles and MacKenzie and of Wechsler, Lieberman, and Read. The large internal friction peak found in ZrH 1.92 (but absent in ZrH 1.6) suggests that it is associated with a stress induced twin interface motion. The relaxation phenomenon appears to be controlled by a diffusion process, presumably that of hydrogen, with an activation energy of about 20 000 calories per mole.

Thermocrystallography of higher hydrides of titanium and zirconium

Low- and high-temperature x-ray diffraction investigations of titanium dihydride (TiH/sub 1.99/) and dideuteride (TiD/sub 1.98/) have indicated apparent 'second-order transformations' in both substances below a critical temperature of 310 deg K. The tetragonal low-temperature phases are distortions of the cubic fluorite high-temperature phases, and are isomorphous with the tetragonal ZrH/sub 2/ structure. A similar study of zirconium dihydride (ZrH/sub 1.92/) has shown that the tetragonality of the lattice of this substance is also temperature- dependent. The critical temperature of the second-order transformation' in ZrH/ sub 1.92/ is unattainable in the present diffraction apparatus owing to dissociation of the hydride. Possible causes of the transformations are discussed. (auth)

The crystal structure of thorium and zirconium dihydrides by X-ray and neutron diffraction

Thorium forms a tetragonal lower hydride of composition ThH{sub 2}. The hydrides ThH{sub 2}, ThD{sub 2} and ZrD{sub 2} have been studied by neutron diffraction in order that hydrogen positions could be determined. The hydrides are isomorphous, and have a deformed fluorite structure. Metal-hydrogen distances in thorium hydride are unusually large, as in UH{sub 3}. Thorium and zirconium scattering amplitudes and a revised scattering amplitude for deuterium are reported.