Abstract
Many Zintl phases exhibiting a CrB type structure form hydrides. Systematic studies of AeTtHx (Ae = Ca, Sr, Ba; Tt = Si, Ge, Sn), LnTtHx (Ln = La, Nd; Tt = Si, Ge, Sn), and LnGaHx (Ln = Nd, Gd) showed the vast structural diversity of these systems. Hydrogenation reactions on REGa (RE = Y, La, Tm) and RESi (RE = Y, Er, Tm) were performed in steel autoclaves under hydrogen pressure up to 5 MPa and temperatures up to 773 K. The products were analyzed by X-ray and neutron powder diffraction. RESi (RE = Y, Er, Tm) form hydrides in the C-LaGeD type. LaGaD1.66 is isostructural to NdGaD1.66 and shows similar electronic features. Ga-D distances (1.987(13) Å and 2.396(9) Å) are considerably longer than in polyanionic hydrides and not indicative of covalent bonding. In TmGaD0.93(2) with a distorted CrB type structure deuterium atoms exclusively occupy tetrahedral voids. Theoretical calculations on density functional theory (DFT) level confirm experimental results and suggest metallic properties for the hydrides.
Highlights
Hydrogenation reactions of intermetallics yield a plethora of compounds with large variation in chemical bonding [1]
Zintl phases are polar intermetallic compounds consisting of an electropositive element M and an element X from group 13–16
Thermal analysis (DSC) of TmGa under hydrogen gas pressure shows an exothermic signal at 430 K (Figure S4)
Summary
Hydrogenation reactions of intermetallics yield a plethora of compounds with large variation in chemical bonding [1]. Zintl phases are polar intermetallic compounds consisting of an electropositive element M (alkali metal, alkaline earth metal, or rare earth metal) and an element X from group 13–16. The electrons of M are being formally transferred to X, which forms a polyanion with a connectivity equal to the isoelectronic element [2,3,4,5]. This simple counting scheme, known as the Zintl–Klemm rule, allows prediction of the connectivity of polyanions
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
