Synthesis and Structural Study of Copper(II) Diarsenates
1996; Elsevier BV; Volume: 121; Issue: 2 Linguagem: Inglês
10.1006/jssc.1996.0047
ISSN1095-726X
AutoresTsung-Chien Chen, Sue‐Lein Wang,
Tópico(s)Magnetism in coordination complexes
ResumoThree new copper(II) diarsenates,ACuAs2O7(A= Ca, Sr, Ba), have been synthesized hydrothermally and characterized by single-crystal X-ray diffraction. All three compounds crystallize in monoclinic system withZ= 4. Crystal data: CaCuAs2O7,a= 7.248(2) Å,b= 8.952(2) Å,c= 9.258(2) Å, β = 109.66(2)°,V= 565.7(3) Å3, space groupP21/c,R= 0.0327; SrCuAs2O7,a= 5.550(1) Å,b= 8.299(2) Å,c= 12.858(3) Å, β = 91.75(3)°,V= 592.0(3) Å3, space groupP21/n,R= 0.0207; BaCuAs2O7,a= 5.736(1),b= 8.458(2),c= 13.044(3) Å, β = 91.16(3)°,V= 632.7(3) Å3, space groupP21/n,R= 0.0373. The structures of these compounds consist of corner-sharing CuO5square pyramids and As2O7disarsenate units. The calcium compound adopts a new structural type. The strontium compound is isotypic with the phosphate analog SrCuP2O7(Moqineet al., J. Solid State Chem.107, 368, 1993). The barium compound adopts the same structure as SrCuAs2O7instead of the triclinic BaCuP2O7(Moqineet al. Acta Crystallogr.C47, 2294, 1991). The relationship between (RA–RB) and space group symmetry as observed in theAIIBIIP2O7system (Elmarzoukiet al.,ACA abstract L07, 1994) does not exist in this diarsenate system. The structures of these diarsenates are discussed along with their phosphate analogues.
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