title: Flux growth and structure of two compounds with the EuIn2P2 structure type, AIn2P2 (A = Ca and Sr), and a new structure type, BaIn2P2.
abstract: Single crystals of the new Zintl phases AIn2P2 [A = Ca (calcium indium phosphide), Sr (strontium indium phosphide) and Ba (barium indium phosphide)] have been synthesized from a reactive indium flux. CaIn2P2 and SrIn2P2 are isostructural with EuIn2P2 and crystallize in the space group P63/mmc. The alkaline earth cations A are located at a site with 3m symmetry; In and P are located at sites with 3m symmetry. The structure type consists of layers of A2+ cations separated by [In2P2]2- anions that contain [In2P6] eclipsed ethane-like units that are further connected by shared P atoms. This yields a double layer of six-membered rings in which the In-In bonds are parallel to the c axis and to one another. BaIn2P2 crystallizes in a new structure type in the space group P2(1)/m with Z = 4, with all atoms residing on sites of mirror symmetry. The structure contains layers of Ba2+ cations separated by [In2P2]2- layers of staggered [In2P6] units that form a mixture of four-, five- and six-membered rings. As a consequence of this more complicated layered structure, both the steric and electronic requirements of the large Ba2+ cation are met.
authors.affiliation: Department of Chemistry, University of California, One Shields Avenue, Davis, CA 95616, USA.
authors.forename: Japheth F
authors.initials: JF
authors.lastname: Rauscher
authors.forename: Cathie L
authors.initials: CL
authors.lastname: Condron
authors.forename: Tanya
authors.initials: T
authors.lastname: Beault
authors.forename: Susan M
authors.initials: SM
authors.lastname: Kauzlarich
authors.forename: Newell
authors.initials: N
authors.lastname: Jensen
authors.forename: Peter
authors.initials: P
authors.lastname: Klavins
authors.forename: Samuel
authors.initials: S
authors.lastname: MaQuilon
authors.forename: Zachary
authors.initials: Z
authors.lastname: Fisk
authors.forename: Marilyn M
authors.initials: MM
authors.lastname: Olmstead