Synthesis, structure and properties of Li2Rh3B2

Li2Rh3B2 has been synthesized at 1000 °C from a stoichiometric mix of rhodium and boron and an excess of lithium. Li2Rh3B2 crystallizes in the orthorhombic space group Pbam (no. 55, Z=2) with room temperature lattice constants a=5.7712(1) Å, b=9.4377(2) Å, c=2.8301(1) Å and cell volume 154.149(6) Å3. The structure was solved from single crystal X-ray diffraction yielding the final R indices (all data) R1=2.8% and wR2=4.7%. The structure is a distortion of the CeCo3B2 structure type, containing a network of Rh6B trigonal prisms and short Li–Li contacts of 2.28(2) Å. Li2Rh3B2 is a diamagnetic metal with a room temperature resistivity of 19 μΩ cm, as determined by magnetic susceptibility and single crystal transport measurements. The measured diamagnetism and electronic structure calculations show that Li2Rh3B2 contains rhodium in a d10 configuration.

Graphical abstractLi2Rh3B2, a diamagnetic metal, has been synthesized from a lithium flux. It adopts a distortion of the CeCo3B2 structure type and is closely related to the 3 K superconductor, LaRh3B2. Pairs of lithium ions (white) fill the channels formed by rhodium–boron trigonal prisms (gray).Figure optionsDownload full-size imageDownload as PowerPoint slide