Novel Alkali Earth Borohydride Sr(BH4)2 and Borohydride-Chloride Sr(BH4)Cl

详细信息    查看全文

• 作者：D. B. Ravnsb忙k ; E. A. Nickels ; R. 膶ern媒 ; C. H. Olesen ; W. I. F. David ; P. P. Edwards ; Y. Filinchuk ; T. R. Jensen
• 刊名：Inorganic Chemistry
• 出版年：2013
• 出版时间：October 7, 2013
• 年：2013
• 卷：52
• 期：19
• 页码：10877-10885
• 全文大小：479K
• 年卷期：v.52,no.19(October 7, 2013)
• ISSN：1520-510X

文摘

Two novel alkali earth borohydrides, Sr(BH₄)₂ and Sr(BH₄)Cl, have been synthesized and investigated by in-situ synchrotron radiation powder X-ray diffraction (SR-PXD) and Raman spectroscopy. Strontium borohydride, Sr(BH₄)₂, was synthesized via a metathesis reaction between LiBH₄ and SrCl₂ by two complementary methods, i.e., solvent-mediated and mechanochemical synthesis, while Sr(BH₄)Cl was obtained from mechanochemical synthesis, i.e., ball milling. Sr(BH₄)₂ crystallizes in the orthorhombic crystal system, a = 6.97833(9) 脜, b = 8.39651(11) 脜, and c = 7.55931(10) 脜 (V = 442.927(10) 脜³) at RT with space group symmetry Pbcn. The compound crystallizes in 伪-PbO₂ structure type and is built from half-occupied brucite-like layers of slightly distorted [Sr(BH₄)₆] octahedra stacked in the a-axis direction. Strontium borohydride chloride, Sr(BH₄)Cl, is a stoichiometric, ordered compound, which also crystallizes in the orthorhombic crystal system, a = 10.8873(8) 脜, b = 4.6035(3) 脜, and c = 7.4398(6) 脜 (V = 372.91(3) 脜³) at RT, with space group symmetry Pnma and structure type Sr(OH)₂. Sr(BH₄)Cl dissociates into Sr(BH₄)₂ and SrCl₂ at 170 掳C, while Sr(BH₄)₂ is found to decompose in multiple steps between 270 and 465 掳C with formation of several decomposition products, e.g., SrB₆. Furthermore, partly characterized new compounds are also reported here, e.g., a solvate of Sr(BH₄)₂ and two Li鈥揝r鈥揃H₄ compounds.