Acta Cryst. (2009). E65, i43  [ doi:10.1107/S1600536809016638 ]

Pr₅Si₃N₉

S. Lupart and W. Schnick

Abstract: Single crystals of Pr₅Si₃N₉, pentapraseodymium trisilicon nonanitride, were obtained by the reaction of elemental praseodymium with silicon diimide in a radio-frequency furnace at 1873 K. The crystal structure consists of a chain-like Si-N substructure of corner-sharing SiN₄ tetrahedra. An additional Q¹-type [SiN₄] unit is attached to every second tetrahedron directed alternately in opposite directions. The resulting branched chains interlock with each other, building up a three-dimensional structure. The central atoms of the Q¹-type [SiN₄] unit and of its attached tetrahedron are situated on a mirror plane, as are two of the four crystallographically unique Pr³⁺ ions. The latter are coordinated by six to ten N atoms, with Pr-N distances similar to those of other rare earth nitridosilicates.

Online 14 May 2009

Copyright © International Union of Crystallography
IUCr Webmaster