title: Pr(5)Si(3)N(9).
abstract: Single crystals of Pr(5)Si(3)N(9), penta-praseodymium trisilicon nona-nitride, were obtained by the reaction of elemental praseo-dymium 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 SiN(4) tetra-hedra. An additional Q(1)-type [SiN(4)] unit is attached to every second tetra-hedron directed alternately in opposite directions. The resulting branched chains inter-lock with each other, building up a three-dimensional structure. The central atoms of the Q(1)-type [SiN(4)] unit and of its attached tetra-hedron are situated on a mirror plane, as are two of the four crystallographically unique Pr(3+) ions. The latter are coordinated by six to ten N atoms, with Pr-N distances similar to those of other rare earth nitridosilicates.
authors.affiliation: Department Chemie und Biochemie, Ludwig-Maximilians-Universität München, Lehrstuhl für Anorganische Festkörperchemie, Butenandtstrasse 5-13, D-81377 München, Germany.
authors.forename: Saskia
authors.initials: S
authors.lastname: Lupart
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Schnick