title: Chains of [RE6] octahedra coupled by (NCN) links in the network structure of RE2Cl(CN2)N. Synthesis and structure of two novel rare earth chloride carbodiimide nitrides with structures related to the RE2Cl3 type.
abstract: Solid state metathesis reactions between RECl(3) (RE = La, Ce) and Li(2)CN(2) at 800 degrees C have led to the discovery of the rare earth chloride carbodiimide nitrides La(2)Cl(CN(2))N (1) and Ce(2)Cl(CN(2))N (2), respectively. Single crystal X-ray diffraction analyses revealed that 1 and 2 crystallize isotypic in an orthorhombic system (Cmmm, Z = 4, a = 13.3914(8) A, b = 9.6345(7) A, c = 3.9568(2) A for 1 and a = 13.340(1) A, b = 9.5267(8) A, c = 3.9402(5) A for 2). The crystal structures of 1 and 2 contain linear chains of edge-sharing octahedra built from rare earth metal atoms. Similar to [M(6)X(8)] type clusters, the [RE(6)] octahedra are capped by eight nitrogen atoms above their faces, of which four are from N(3-) ions and the other four are from (CN(2))(2-) ions. The chains are interconnected by bridging (CN(2))(2-) to form a three-dimensional network with Cl(-) ions in linear channels. Compounds 1 and 2 are surprisingly stable toward air and water. They have been characterized by thermal analysis, infrared spectroscopy, and magnetic susceptibility studies.
authors.affiliation: Institute of Inorganic Chemistry, University of Tübingen, D-72076 Tübingen, Germany.
authors.forename: Radhakrishnan
authors.initials: R
authors.lastname: Srinivasan
authors.forename: Markus
authors.initials: M
authors.lastname: Ströbele
authors.forename: H-Jürgen
authors.initials: HJ
authors.lastname: Meyer