Synthesis and crystal structure of solvent-free dodecahydro closo-dodecaborate of nickel, NiBH.

Nickel closo-dodecaborate NiB12H12 was prepared by mechanosynthesis (ball milling) of mixtures of Na2B12H12 + NiCl2 followed by hydration and drying under dynamic vacuum. The crystal structures of hydrated and anhydrous closo-dodecaborates were characterized by temperature dependent synchrotron radiation X-ray powder diffraction, ab initio calculations, thermal analysis and infrared spectroscopy. Three different water containing complexes were found: a homoleptic octahedral complex in Ni(H2O)6B12H12 crystallizing in two different deformation variants of a complex centred closo-dodecaborate cube, and a heteroleptic octahedral complex in Ni(H2O)4B12H12 containing four water molecules and two hydrogens and centring also a deformed closo-dodecaborate cube.

Halide Free M(BH4)2 (M = Sr, Ba, and Eu) Synthesis, Structure, and Decomposition.

Borohydrides have attained high interest in the past few years due to their high volumetric and gravimetric hydrogen content. Synthesis of di/trimetallic borohydride is a way to alter the thermodynamics of hydrogen release from borohydrides. Previously reported preparations of M(BH4)2 involved chloride containing species such as SrCl2.