2010  2004 

2010

  • Al3Li4(BH4)13: A Complex Double-Cation Borohydride with a New Structure
    I. Lindemann, R.D. Ferrer, L. Dunsch, Y. Filinchuk, R. Cerný, , , , L. Schultz and O. Gutfleisch
    Chemistry - A European Journal, 16 (2010), p8707-8712
    Keywords: borohydrides; density functional calculations; hydrogen storage; metathesis; X-ray diffraction
    DOI:10.1002/chem.201000831 | unige:14778 | Abstract | Article PDF
 
The new double-cation Al-Li-borohydride is an attractive candidate material for hydrogen storage due to a very low hydrogen desorption temperature (~70 °C) combined with a high hydrogen density (17.2 wt %). It was synthesised by high-energy ball milling of AlCl3 and LiBH4. The structure of the compound was determined from image-plate synchrotron powder diffraction supported by DFT calculations. The material shows a unique 3D framework structure within the borohydrides (space group=P-43n, a=11.3640(3) Å). The unexpected composition Al3Li4(BH4)13 can be rationalized on the basis of a complex cation [(BH4)Li4]3+ and a complex anion [Al(BH4)4]-. The refinements from synchrotron powder diffraction of different samples revealed the presence of limited amounts of chloride ions replacing the borohydride on one site. In situ Raman spectroscopy, differential scanning calorimetry (DSC), thermogravimetry (TG) and thermal desorption measurements were used to study the decomposition pathway of the compound. Al-Li-borohydride decomposes at ~70 °C, forming LiBH4. The high mass loss of about 20 % during the decomposition indicates the release of not only hydrogen but also diborane.

2004

  • Cobalt(II)-tris-2,2'-bipyridine as a Spin-Crossover Complex: Evidence for Cooperative Effects in Three-Dimensional Oxalate Networks
    M. Zerara and
    ChemPhysChem, 5 (3) (2004), p395-399
    Keywords: cooperative effects; host-guest systems; magnetic properties; spin crossover; X-ray diffraction
    DOI:10.1002/cphc.200301044 | unige:3257 | Abstract | Article HTML | Article PDF
In the three-dimensional oxalate network structures of composition [CoxMII1-x(bpy)3][MICr(ox)3], the spin state of the [Cox(bpy)3]2+ complex can be tuned by means of chemical pressure. With MI=Na it is a classic high-spin complex. Substitution of Na by Li stabilises the complex and it becomes a spin-crossover complex. Dilution with MII=Fe reinforces this effect, and MII=Zn reverses it.

 2010  2004 

Author list

Download this list in format   RIS     EndNote     BibTex     PDF    XML  



Last update Friday May 17 2013