Alkali metal - yttrium borohydrides: The link between coordination of small and large rare-earth

作者：Sadikin Yolanda; Stare Katarina; Schouwink Pascal; Ley Morten Brix; Jensen Torben R; Meden Anton; Cerny Radovan^*

来源：Journal of Solid State Chemistry, 2015, 225: 231-239.

DOI：10.1016/j.jssc.2014.12.018

• Borohydride
• Powder diffraction
• Perovskite

The system Li-A-Y-BH4 (A=K, Rb, Cs) is found to contain five new compounds and four further ones known from previous work on the homoleptic borohydrides. Crystal structures have been solved and refined from synchrotron X-ray powder diffraction, thermal stability of new compounds have been investigated and ionic conductivity measured for selected samples. Significant coordination flexibility for y3+ is revealed, which allows the formation of both octahedral frameworks and tetrahedral complex anions with the tetrahydroborate anion BH4 both as a linker and terminal ligand. Bi- and trimetallic cubic double-perovskites c-A(3)Y(BH4)(6) or c-A(2)LiY(BH4)(6) (A =Rb, Cs) form in all the investigated systems, with the exception of the Li-K-Y system. The compounds with the stoichiometry AY(BH4)(4) crystallize in all investigated systems with a great variety of structure types which find their analog amongst metal oxides. In-situ formation of a new borohydride - closo-borane is observed during decomposition of all double perovskites.

• 出版日期2015-5