Structure of an unusual, 8-coordinate, exclusive cryptate of ytterbium(III) containing multiple nitrato andN-thiocyanato ligands

Abstract

The first example of an 8-coordinate cryptate of cryptand(2,2,2) [N(CH₂CH₂OCH₂CH₂OCH₂CH₂)₃N], Yb³⁺, and multiple nitrato andN-thiocyanato ligands, H₂Yb(NCS)₃(NO₃)₂(2,2,2)·H₂O (I), has been synthesized. The crystal and molecular structure ofI have been determined by single-crystal X-ray diffraction. The Yb³⁺ cation is not located in the cavity of the cryptand(2,2,2), but is connected to it through a water bridge by two hydrogen bonds to form an exclusive cryptate. The two H⁺ ions are mostly probably bound to the two N atoms of cryptand(2,2,2). The coordinating atoms of the NO ⁻₃ , NCS⁻, and H₂O ligands constitute a trigonododecahedron around the central Yb³⁺ ion. CryptateI crystallizes in the monoclinic space groupP2_l/n withZ=4. The finalR factor for 3659 independent reflections, following correction for Lorentz and polarization effects and havingF ₀>5σ(F ₀), is 0.053. Infrared spectroscopic data for1 are consistent with the X-ray crystal structure results.