Erbium(III) and lutecium(III) complexes [Ln(H2O)8][Cr(NCS)6] · 5H2O: Synthesis and crystal structure

[Ln(H2O)8][Cr(NCS)6] · 5H2O aqua complexes, where Ln = Er (1), Lu (2), have been found in an aqueous solution instead of binary complex salts with an organic ligand in their cation, when crystal products of the reaction between Ln(NO3)3 · 6H2O (Ln = Er, Lu), K3[Cr(NCS)6] · 4H2O, and 8-oxyquinoline (C9H7NO) were studied by X-ray diffraction. Crystals of complexes 1 and 2 are isostructural and crystallize in triclinic system, space group P\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\bar 1$$\end{document}, Z = 2. For complex 1: a = 9.0677(4) Å, b = 9.3115(4) Å, c = 16.9595 Å, α = 81.526(2)°, β = 86.153(2)°, γ = 83.879(2)°, V = 1406.33(10) Å3, ρcalc = 1.894 g/cm3; for complex 2: a = 9.0438(3) Å, b = 9.2880(3) Å, c = 16.9181(3) Å, α = 81.7250(10)°, β = 86.1600(10)°, γ = 83.8850(10)°, V = 1396.38(7) Å3, ρcalc = 1.926 g/cm3.