The chiral structure induced by lone-pair electrons: syntheses and characterization of two novel chiral rare-earth selenites containing homochiral helical chains

Two novel layered chiral rare-earth selenites [Ln(H2O)(HSeO3)(SeO3)] H2O (LnZDy, 1, and Gd, 2) have been hydrothermally synthesized and characterized by the elemental analyses, IR spectra, XPS spectra, TG analyses and the single crystal X-ray diffraction. Compound 1 crystallizes in the orthorhombic system, space group P212121, with aZ6.5767(13) A ° , bZ6.9320(14) A ° , cZ16.333(3) A ° , and ZZ4. Compound 2 crystallizes in the orthorhombic system, space group P212121, with aZ6.6216(13) A ° , bZ7.0086(14) A ° , cZ16.424(3) A ° , and ZZ4. Compounds 1 and 2 are isostructural, and both exhibit interesting chiral layer constructed from {Ln(H2O)(HSeO3)}n left-handed helical chains linked by [SeO3]2K anions. Furthermore, the chiral layers are connected by strong hydrogen bonding interactions to form the three-dimensional structure with chiral channels along the [100] directions. q 2004 Elsevier B.V. All rights reserved.