Lanthanide(III) Hexa(thiocyanato-N)chromate(III) Complexes with Dimethyl Sulfoxide: Synthesis and Crystal Structure

Double complexes [Ln(DMSO)8][Cr(NCS)6], where Ln = Nd (1), Eu (2), Gd (3), Dy(4), Ho (5), Lu (6), Tb (7), or Yb (8), synthesized by the reaction between aqueous solutions of Ln(NO3)3 and K3[Cr(NCS)6] and dimethyl sulfoxide C2H6SO (DMSO) have been studied by IR spectroscopy and single-crystal X-ray diffraction. Single crystals of compounds for XRD were obtained by isothermal recrystallization of complex powders from DMSO solutions. Compounds 1–8 are isostructural, crystallize in the triclinic system, space group P $$\overline 1 $$ . The crystal structure is island with [Ln(DMSO)8]3+ cations and [Cr(NCS)6]3– anions. The asymmetric unit comprises two cations and two anions. The coordination environment of the Ln atom consists of eight O atoms of DMSO molecules located at the vertices of a distorted square antiprism. In isolated [Cr(NCS)6]3– anions, the chromium(III) coordination polyhedron is close to a regular octahedron and consists of N atoms of six NCS ions. The center packing of complex cations and anions is a distorted NaCl structure.