Discrete [Yb(NCS)3(H2O)5] Molecules in Pentaaquatriisothiocyanatoytterbium(III) Monohydrate

Abstract

Single crystals of [Yb(NCS)3(H2O)5]·H2O were synthesized from a salt‐metathesis reaction between stoichiometric amounts of aqueous solutions of Yb2(SO4)3·8H2O and Ba(NCS)2·3H2O driven by the precipitation of Ba(SO4), followed by isothermic evaporation of the filtered‐off solution at room temperature under atmospheric conditions. These crystals of the title compound came as transparent, colorless and hygroscopic needles. According to the X‐ray diffraction structure analysis [Yb(NCS)3(H2O)5]·H2O crystallizes in the monoclinic space group P21 with the lattice parameters a = 845.38(5), b = 719.26(4), c = 1219.65(7) pm, β = 103.852(3)° for Z = 2. The acentric crystal structure contains crystallographically unique Yb3+ cations, each surrounded by three thiocyanate anions, all grafting with their nitrogen atoms, and five water molecules forming a neutral [Yb(NCS)3(H2O)5] complex with square antiprismatic shape, completed by a sixth interstitial water molecule. ATR‐FT infrared and single‐crystal Raman spectra of [Yb(NCS)3(H2O)5]·H2O confirm these findings.