Dynamic Disorder of Bi82+ Clusters in the Plastic Phase (Bi8)3Bi[InI4]9

Aron Wosylus (1) , Vitaly Dubenskyy (1) , Ulrich Schwarz (2) , Michael Ruck (3)

1 Fachrichtung Chemie und Lebensmittelchemie
2 CPfS - Max-Planck-Institut für Chemische Physik fester Stoffe
3 Fachrichtung Chemie und Lebensmittelchemie

Black, air-insensitive crystals of the bismuth-rich tetraiodido-indate(III) (Bi8)3Bi[InI4]9 have been prepared from melts of the contributing elements. X-ray diffraction on a single crystal at 293 K and 220 K revealed a cubic structure with [InI4]– tetrahedra, isolated Bi3+ cations and rotationally disordered Bi82+ square antiprisms (space group Fm-3c; a = 20.162(2) Å at T = 293(1)). The principal arrangement of the complex ions corresponds to the AuCu3 type. The small bulk modulus B0 = 12(1) GPa and its large pressure derivative B0’ = 11(1) as well as the low Debye temperature θD = 52 K are in accordance with a plastic behavior. Cooling below 148(1) K induces the first order transition into an ordered phase with 0.43 % higher density but much larger unit cell and lower crystallographic point group. The transition enthalpy ΔH ≈ 3.8 kJ•mol–1 and transition entropy ΔS ≈ 3 R were determined from specific heat data. A similar reversible phase transition into a lower symmetric structure is observed at a pressure of approximately 5 GPa. (Bi8)3Bi[InI4]9 is a diamagnetic semiconductor.

Mots clés: Physical Sciences

Aron Wosylus, Vitaly Dubenskyy, Ulrich Schwarz, Michael Ruck. Dynamic Disorder of Bi82+ Clusters in the Plastic Phase (Bi8)3Bi[InI4]9. Journal of Inorganic and General Chemistry / Zeitschrift für anorganische und allgemeine Chemie, 2009, 635 (6-7), pp.1030. ⟨10.1002/zaac.200900035⟩. ⟨hal-00484130⟩