The lithium-rich stannide Li4Rh3Sn5.
SREERAJ, Puravankara; DINGES, Tim; KÖSTERS, Jutta; SCHAPPACHER, Falko Mark; ECKERT, Hellmut; PÖTTGEN, Rainer.
SREERAJ, Puravankara; DINGES, Tim; KÖSTERS, Jutta; SCHAPPACHER, Falko Mark; ECKERT, Hellmut; PÖTTGEN, Rainer.
Abstract: The stannide Li4Rh3Sn5 was synthesized by induction-melting of the elements in a sealed tantalum ampoule. The sample was characterized by powder X-ray diffraction and the Li4Rh3Sn5 structure was refined from single-crystal X-ray diffractometer data: new type, orthorhombic space group Pnnm, a = 813.27(11), b = 2,259.6(3), c = 449.94(6) pm, wR2 = 0.0486, 1577 F 2 values and 64 variables. The rhodium and tin atoms form a rigid covalently bonded three-dimensional [Rh3Sn5] network with Rh-Sn distances ranging from 263 to 277 pm. Within this network, the tin atoms form two different substructures, i. e., angled Sn1-Sn4-Sn5 units and isolated Sn2 and Sn3 atoms. The lithium atoms fill cages within the [Rh3Sn5] network. They have coordination numbers 11, 12 and 13. Based on their different 7Li resonance shifts two groups of distinct local environments can be identified in an intensity ratio of 3:1, namely the 4g Wyckoff sites Li1, Li2, and Li5, and the 2c Wyckoff sites Li3 and Li4. The whole Li4Rh3Sn5 structure can be described by condensation of the Li1@LiRh4Sn6, Li2@Li2Rh4Sn6, Li3@Li2Rh4Sn6, and Li4@Li2Rh4Sn6 polyhedra, including the Li5 atoms which are within the Li1 coordination sphere. The 119Sn Mössbauer spectrum of Li4Rh3Sn5 shows a superposition of two sub-signals in a ratio of 60:40. The two sub-signals with similar isomer shift are discernable through their quadrupole splitting parameters: ~1.93 mm s-1 for the tin atoms of the angled Sn3 unit, and ~1.20 mm s-1 for the isolated tin atoms with a more symmetric electron density distribution.
@article={003244530,author = {SREERAJ, Puravankara; DINGES, Tim; KÖSTERS, Jutta; SCHAPPACHER, Falko Mark; ECKERT, Hellmut; PÖTTGEN, Rainer.},title={The lithium-rich stannide Li4Rh3Sn5},journal={Zeitschrift für Naturforschung B},note={v. 80, n. 3-4, p. 71-78 + supplementary material},year={2025}}