Facile Formation of Thermodynamically Unstable Novel Borohydride Materials by a Wet Chemistry Route

• Published in: Chemistry : a European journal 2015-04, Vol.21 (15), p.5689-5692
• Main Authors: Jaroń, Tomasz, Wegner, Wojciech, Fijałkowski, Karol J., Leszczyński, Piotr J., Grochala, Wojciech
• Format: Article
• Language: English
• Subjects: Bimetals; Borohydrides; Chemistry; Crystal structure; Derivatives; Drying; hydrogen storage materials; Phases; weakly coordinating anions; wet chemistry; Yttrium
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201404968

A novel wet synthetic method utilizing weakly coordinating anions that yields LiCl‐free Zn‐based materials for hydrogen storage has recently been reported. Here we show that this method may also be applied for the synthesis of the pure yttrium derivatives, M[Y(BH4)4] (M=K, Rb, Cs). Moreover, it can be extended to the preparation of previously unknown thermodynamically unstable derivatives, Li[Y(BH4)4] and Na[Y(BH4)4]. Importantly, these two H‐rich phases cannot be accessed by standard dry (mechanochemical) or solid/gas synthetic methods due to the thermodynamic obstacles. Here we describe their crystal structures and selected important physicochemical properties. The Y and the wherefore: The applicability of a novel wet synthetic method yielding LiCl‐free products is demonstrated for bimetallic yttrium derivatives, MY(BH4)4 (M=K, Rb, Cs). This method may also be extended to the preparation of as yet unknown thermodynamically unstable derivatives, Li[Y(BH4)4] and Na[Y(BH4)4], which are inaccessible using the mechanochemical chemistry route.