Synthèse et propriétés des pentaméthyl-2,3,3,5,5 et tétraméthyl-3,3,5,5 N-pipéridinométhyl-2 cyclohexanones et de leurs dérivés

1975 ◽  
Vol 53 (21) ◽  
pp. 3294-3298 ◽  
Author(s):  
Jean-Claude Richer ◽  
Raphael Arlotto
Keyword(s):  
Complex Hydrides

The preparation is reported of 2-methylene- and of 2-butylthiomethylene-3,3,5,5-tetramethylcyclohexanone as is their transformation into 2,3,3,5,5-pentamethylcyclohexanone. The synthesis of 2-N-piperidinomethyl-3,3,5,5-tetramethylcyclohexanone is described. The properties of the ketones as well as the stereochemistry of their reduction by complex hydrides was examined. [Journal translation]

Lithium-ion diffusivity in complex hydrides: Pulsed-field-gradient NMR studies of LiLa(BH4)3Cl, Li3(NH2)2I and Li-1-CB9H10

2021 ◽  
Vol 362 ◽  
pp. 115585
Author(s):  
A.V. Skripov ◽  
G. Majer ◽  
O.A. Babanova ◽  
R.V. Skoryunov ◽  
A.V. Soloninin ◽  
...  
Keyword(s):  
Field Gradient ◽  
Lithium Ion ◽  
Nmr Studies ◽  
Pulsed Field Gradient Nmr ◽  
Pulsed Field ◽  
Complex Hydrides

scholarly journals Complex transition metal hydrides: linear correlation of countercation electronegativity versus T–D bond lengths

2015 ◽  
Vol 51 (56) ◽  
pp. 11248-11251 ◽  
Author(s):  
T. D. Humphries ◽  
D. A. Sheppard ◽  
C. E. Buckley
Keyword(s):  
Transition Metal ◽  
Bond Length ◽  
Linear Correlation ◽  
Metal Hydrides ◽  
Bond Lengths ◽  
Transition Metal Hydrides ◽  
Complex Hydrides

For homoleptic 18-electron complex hydrides, an inverse linear correlation has been established between the T–deuterium bond length and the average electronegativity of the metal countercations.

Nickel macrocycles with complex hydrides—new avenues for hydrogen storage research

2010 ◽  
Vol 3 (12) ◽  
pp. 1973 ◽  
Author(s):  
Andrew James Churchard ◽  
Michał Ksawery Cyranski ◽  
Łukasz Dobrzycki ◽  
Armand Budzianowski ◽  
Wojciech Grochala
Keyword(s):  
Hydrogen Storage ◽  
Complex Hydrides

scholarly journals Phase Transitions in Borohydride Perovskites

2014 ◽  
Vol 70 (a1) ◽  
pp. C73-C73
Author(s):  
Pascal Schouwink ◽  
Radovan Cerny
Keyword(s):  
Phase Transitions ◽  
Volume Expansion ◽  
Host Lattice ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
New Class ◽  
Structural Distortions ◽  
Complex Hydrides ◽  
Type Lattice

A series of complex hydrides based on the highly dynamic tetrahydroborate anion BH4-and crystallizing in theABX3type lattice has recently been discovered. They present a rare case of a family of iono-covalent hydrides that has a genuine tunable host lattice, making them an interesting new class of host compounds for not only the design of hydrogen storage materials but also hydride-properties related to heavy metals. Amongst these, preliminary results onREE-based luminescence will be discussed in the neat and doped compounds, the Ln2+excited states surprisingly not being subject to significant quenching by B-H vibrations. Unlike oxide- or halide-perovskites some members of theAB(BH4)3group do not evolve to higher symmetries as a function of temperature. We show by means ofin-situsynchrotron X-ray powder diffraction, vibrational spectroscopy andab initiocalculations in the solid state, that temperature-induced structural distortions in perovskite-typeACa(BH4)3(A= K, Rb, Cs) have their origin in close hydridic di-hydrogen contacts of repulsive nature. Coupling between internal B-H vibrations and phonons results in lattice distortions that are identical in symmetry to well-known instabilities (soft modes) in perovskites, which generally condense to lower temperatures. Anion-substitution BH4-<->X-(X= Halide) calculated on ordered models can relax distortions caused by repulsive effects. High temperature phase-transitions inACa(BH4)3can be of first or second-order, including 2-fold superlattices, simple cubic-cubic transitions accompanied by volume expansion or complex modulated superstructures accompanied by negative volume expansion, as is the case in RbCa(BH4)3. Close di-hydrogen contacts may be suggested as a tool to tailor the crystal symmetry in complex hydride perovskites in the future.

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