ChemInform Abstract: Facile Formation of Thermodynamically Unstable Novel Borohydride Materials by a Wet Chemistry Route.

Abstract

Facile Formation of Thermodynamically Unstable Novel Borohydride Materials by a Wet Chemistry Route. -M[Y(BH 4)4] (M: Li, Na, K, Rb, Cs) compounds are prepared by ball milling (20-30 min) of a 1:1:3 molar mixture of anhydrous YCl 3, (Bu4N)BH4, and LiBH4 (5 mol% excess) followed by extraction of (Bu4N)[Y(BH4)4] with CH 2Cl2 (DCM) and CHCl3 and subsequent solvent evaporation. Solutions of M[Al{OC(CF 3)3}4] in DCM are then combined with the latter precursor (15-120 min stirring) to form the products in yields of >95%. The method results in "dead mass" free compounds suitable for application as H 2 storage material as demonstrated by TGA of the thermodynamically stable Cs compound. The unstable Li and Na compounds are not accessible by standard mechanochemical routes. They crystallize in the space groups P42c and Cmcm (powder XRD), respectively. -(JARON*, T.; WEGNER, W.; FIJALKOWSKI, K. J.; LESZCZYNSKI, P. J.; GROCHALA, W.; Chem. -Eur. J. 21 (2015) 15, 5689-5692, http://dx.doi.org/10.1002/chem.201404968 ; Cent. New Technol., Univ. Warsaw, PL-02-089 Warsaw, Pol.; Eng.) -J. Schramke 28-013