Acta Phys. -Chim. Sin. ›› 1993, Vol. 9 ›› Issue (05): 687-691.doi: 10.3866/PKU.WHXB19930522

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Synthesis and Structure of CsSm2I5 and CsSmI3

Chen Xian-Zhong; Wang Shi-Hua; He Guan-You; Zhao Xin-Hua; Jiang Sheng-Bang   

  1. Department of Chemistry, Beijing Normal University, Beijing 100875
  • Received:1992-03-13 Revised:1992-06-11 Published:1993-10-15
  • Contact: Wang Shi-Hua

Abstract: The ternary iodides CsSm_2I_5 and CsSmI_3 which contain a divalentt rare earth cation have been synthesized by direct reaction of SmI_2 with CsI and by reaction between Sm, HgI_2 and CsI. Their crystal structures are determined by X-ray powder diffraction technique. CsSm_2I_5 is isostruetural with NH_4Pb_2Cl_5 (monoclinic, p2_1/c) a=1.0219(3) nm, b=9.093(2) nm, c=1.4300(6) nm, β=90.35(4)°, z=4, D_0=5.26 g·cm~(-3) at 25 ℃, D_x=5.34 g·cm~(-3) and MV_x=200.0 cm·mol~(-1). CsSmI_3 is Iso-structural with SrCeO_3 (orthorhombic, Pmmm), a=0.8631(3) nm, b=1.7999(6) nm, c=1.2564(5) nm, z=8, D_0=4.76 g·cm~(-3) at 25 ℃, D_x=4.52 g·cm~(-3), and MV_x=146.9 cm·mol~(-1). The valency of samarium in both compounds were determined and confirmed to be +2 by polarographic analyzer and fluorescence spectra.

Key words: One-step synthesis, CsSm2I5, CsSmI3, Structure, Fluorescence spectra