title: APdCu(Se2)(Se3) (A = K and Rb): new quaternary copper palladium polyselenides with unusual metal-selenium coordination.
abstract: Two novel metal polyselenides, KPdCu(Se(2))(Se(3)) (I) and RbPdCu(Se(2))(Se(3)) (II), have been synthesized from solvothermal reactions in superheated ethylenediamine at 160 degrees C. The isostructural compounds crystallize in the monoclinic space group P2(1)/m, Z = 2, with a = 6.145(1) A, b = 7.268(1) A, c = 8.865(2) A, beta = 102.41(3) degrees for I, and a = 6.253(1) A, b = 7.267(1) A, c = 8.993(2) A, beta = 102.28(3) degrees for II. Their crystal structures are two-dimensional networks with [PdCu(Se(2))(Se(3))](-) anionic layers built from one-dimensional [Pd(Se(2))(Se(3))](2)(-) "chains" that are "stitched" together by tetrahedrally coordinated Cu atoms. The DSC data show that I and II are stable up to 400 degrees C and decompose at ca. 436 and 424 degrees C, respectively. Both compounds are narrow band-gap semiconductors with estimated band gaps of about 0.7 eV (I) and 0.8 eV (II), respectively. They are the first structurally characterized quaternary copper palladium polychalcogenides with a (Se(2))(2)(-) and a (Se(3))(2)(-) fragment, both exhibiting interesting and unusual metal-selenium coordination.
authors.affiliation: Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854, USA.
authors.forename: Xuean
authors.initials: X
authors.lastname: Chen
authors.forename: Kieran J
authors.initials: KJ
authors.lastname: Dilks
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Huang
authors.forename: Jing
authors.initials: J
authors.lastname: Li