Synthesis, Crystal Structure, and Thermal Decomposition of Strontium Amidoborane

Strontium amidoborane, Sr(NH 2 BH 3 ) 2, is synthesized by gently milling the powder mixtures of SrH 2 and ammonia borane (in a 1:2 molar ratio), followed by isothermally processing the postmilled mixtures at 45 °C for 2 h. It is found that Sr(NH 2 BH 3 ) 2 crystallizes with a monoclinic structure in space group C 2, with lattice parameters a = 8.1660(4) Å, b = 5.0969(3) Å, c = 6.7258(4) Å, and β = 94.392(4)°, and with Z = 2. In the structure, each Sr 2+ bonds with two [NH 2 BH 3 ] 2− ions with a Sr−N distance of 2.68 Å. Thermal analyses show that the decomposition of Sr(NH 2 BH 3 ) 2 into Sr(NBH) 2 and H 2 initiates at about 60 °C and becomes violent as the temperature increases to 93 °C in the heating process at a rate of 2 °C min −1 . With the release of H 2, a considerable amount of NH 3 and small amounts of B 2 H 6 are also emitted due to the decomposition of Sr(NBH) 2 .