STRUCTURE OF AN UNUSUAL, 8-COORDINATE, EXCLUSIVE CRYPTATE OF YTTERBIUM(III) CONTAINING MULTIPLE NITRATE AND N-THIOCYANATO LIGANDS

The first example of an and coordinate cryptate of cryptand(2,2,2) [N( CH2CH2OCH2CH2OCH2-CH2)(3)N], Yb3+, and multiple nitrate and N-thiocyan ato ligands, H-2,Yb(NCS)(3)(NO3)(2)(2,2,2) H2O (I), has been synthesiz ed. The crystal and molecular structure of I have been determined by s ingle-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 NO3-, NCS-, and H2O ligands constitute a trigonododecahedron around the central Yb3+ ion. Cryptate I crystal lizes in the monoclinic space group P2(/)n with Z = 4. The final R fac tor for 3659 independent reflections, following correction for Lorentz and polarization effects and having F-0 > 5 sigma(F-0), is 0.053. Inf rared spectroscopic data for 1 are consistent with the X-ray crystal s tructure results.