title: Role of the Li(+) node in the Li-BH4 substructure of double-cation tetrahydroborates.
abstract: The phase diagram LiBH4-ABH4 (A = Rb,Cs) has been screened and revealed ten new compounds LiiAj(BH4)i+j (A = Rb, Cs), with i, j ranging between 1 and 3, representing eight new structure types amongst homoleptic borohydrides. An approach based on synchrotron X-ray powder diffraction to solve crystal structures and solid-state first principles calculations to refine atomic positions allows characterizing multi-phase ball-milled samples. The Li-BH4 substructure adopts various topologies as a function of the compound's Li content, ranging from one-dimensional isolated chains to three-dimensional networks. It is revealed that the Li(+) ion has potential as a surprisingly versatile cation participating in framework building with the tetrahydroborate anion BH4 as a linker, if the framework is stabilized by large electropositive counter-cations. This utility can be of interest when designing novel hydridic frameworks based on alkaline metals and will be of use when exploring the structural and coordination chemistry of light-metal systems otherwise subject to eutectic melting.
authors.affiliation: Department of Condensed Matter Physics, Laboratory of Crystallography, University of Geneva, Quai Ernest-Ansermet 24, 1211 Geneva, Switzerland.
authors.forename: Pascal
authors.initials: P
authors.lastname: Schouwink
authors.affiliation: Institute of Inorganic Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, 845 36 Bratislava, Slovakia.
authors.forename: Lubomír
authors.initials: L
authors.lastname: Smrčok
authors.affiliation: Department of Condensed Matter Physics, Laboratory of Crystallography, University of Geneva, Quai Ernest-Ansermet 24, 1211 Geneva, Switzerland.
authors.forename: Radovan
authors.initials: R
authors.lastname: Černý
keywords: homoleptic borohydrides; phase diagram; solid-state calculations