Salts of highly fluorinated weakly coordinating anions as versatile precursors towards hydrogen storage materials. Issue 45 (5th August 2015) - Starobrat, A.
Abstract : Metathetic reactions using salts of highly-fluorinated weakly coordinating anions permit synthesis of high-purity hydrogen storage materials. Abstract : We report the most recent results related to application of a metathetic pathway towards mixed-metal borohydrides. The synthetic protocol utilizes highly-fluorinated weakly coordinating anion salts as precursors. We discuss the technicalities related to the use of fluorine-rich anions as well as the improvements which are still needed to deliver high-purity materials with potential applications for hydrogen storage. The applicability of the method is expanded beyond the previously described complex borohydrides of alkali metal Zn or Y, towards the systems containing Mg II, Sc III, Mn II, or Eu III . We have prepared for the first time [Ph4 P]2 [Mn(BH4 )4 ] and [Me4 N]2 [Mg(BH4 )4 ], solved their crystal structures from powder x-ray diffraction, and used selected organic metal borohydride derivatives as precursors towards mixed-metal borohydrides (K2 Mn(BH4 )4, Rb3 Mg(BH4 )5, etc .). We have also prepared [Ph4 P][Eu(BH4 )4 ], which is the first derivative of Eu III in the homoleptic environment of borohydride anions.