ChemInform Abstract: The Ternary Alkali Metal Platinum Borides LiPt3B (I), NaPt3B1+x (II) and Na3Pt9B5 (III) - New Structure Variants of the CeCo3B2 Type.
Abstract
The title compounds (I), (II), and (III) are prepared by reaction of the elements in sealed Ta-tubes at 1000 °C. (I) crystallizes in the hexagonal space group P62m with Z=3.
ChemInform Abstract
The title compounds (I), (II), and (III) are prepared by reaction of the elements in sealed Ta-tubes at 1000 °C. (I) crystallizes in the hexagonal space group P62m with Z=3. (II), 0 ≤ x ≤ 0.45, is also hexagonal, P6/mmm, Z=2, and (III) is orthorhombic, Cmcm, Z=4. Three new structure variants of the CeCo3B2-type are formed due to the boron deficiency of these compounds when compared with CeCo3B2. In (II) with x = 0, only every second layer of the trigonal Pt prisms is occupied by B, whereas the prisms of (I) are shifted against each other, thus generating new smaller Pt polyhedra which are unable to accomodate B atoms. The structure of (III) is derived from the CeCo3B2-type by chemical twinning.
