2011 Volume 52 Issue 7 Pages 1443-1446
The existence of Mg(B12H12) as an intermediate compound during the dehydrogenation process of Mg(BH4)2 has been verified. To elucidate the formation process of Mg(B12H12), the dehydrogenation products of Mg(BH4)2 at different temperatures were characterized via X-ray diffraction and 11B magic angle spinning NMR measurements. The experimental results indicate that several new intermediate compounds such as Mg(B2H6) and Mg(B5H9) or Mg(B5H8)2 are expected to be formed prior to the formation of Mg(B12H12). Thus, it is suggested that the formation of [B12H12]2− from [BH4]− occurs via the gradual evolution of the B-H complex anion, i.e., [BH4]−→[B2H6]2−→[B5H9]2− or [B5H8]−→[B12H12]2−.