SYNTHETIC AND STRUCTURAL STUDIES OF NONAMETALLIC TERT-BUTOXIDE MIXED-METAL COMPLEXES OF YTTRIUM, EUROPIUM, AND SODIUM - X-RAY CRYSTAL-STRUCTURES OF A NEW CLASS OF LNNA8(OR)10X COMPLEXES (LN = Y, EU, R = CME3, X = CL, OH)

LnCl3 (Ln = Y, Eu) reacts with 10 equiv of NaOCMe3 in THF to form LnNa8(OCMe3)10Cl, which can be isolated in 70-90% yield by removal of solvent, washing with hexane, and extraction with toluene. EuNa8(OCMe3)10Cl (1) crystallizes from toluene in space group Pbca with unit cell parameters at 203 K of a = 20.395(4) angstrom, b = 27.506(5) angstrom, c = 21.496(4) angstrom, V = 12059(4) angstrom3, and D(calcd) = 1.21 g cm-3 for Z = 8. Least-squares refinement of the model based on 4844 reflections (\F(o)\ > 4.0sigma(\F(o)\)) converged to a final R(F) = 6.4%. YNa8(OCMe3)10Cl (2) crystallizes from toluene in space group Pbca with unit cell parameters at 203 K of a = 20.270(3) angstrom, b = 27.332(4) angstrom, c = 21.409(3) angstrom, V = 11861(3) angstrom3, and Z = 8 for D(calcd) = 1.16 g cm-3. Least-squares refinement of the model based on 4877 observed reflections converged to a final R(F) = 8.9%. The nine metals in 1 and 2 describe a capped square antiprism which has the lanthanide metal in the capping position. The metal atoms are linked by eight mu3-OCMe3 groups and one mu4-OCMe3 group which caps the square face opposite the lanthanide capping position. One terminal OCMe3 group is attached to the lanthanide metal center. The chloride atom in 1 occupies a position inside the polyhedron of metals and is located 0.93 angstrom below the Na4 plane closest to europium and 2.02 angstrom above the other Na4 plane. In 2, the chloride is similarly situated with analogous (Na4 plane)-Cl distances of 0.82 and 2.12 angstrom, respectively. An isostructural hydroxide analog of 1 and 2, YNa8(OCMe3)10(OH)(3), has also been isolated. Complex 3 crystallizes from toluene in space group Pbca with unit cell parameters at 295 K of a = 20.423(3) angstrom, b = 27.370(5) angstrom, c = 21.633(4) angstrom, V = 12 092(4) angstrom3, and Z = 8 for D(calcd) = 1.12 g cm-3. Least-squares refinement of the model based on 28 15 observed reflections converged to a final R(F) = 12.2%. The isolation of 1 and 2 from reactions of LnCl3 With NaOCMe3 depends critically on how the initial reaction mixture is handled. 1 is also observed as a product from the reaction of EuCl3 with 3 equiv of NaOCMe3, although the yields vary drastically depending on isolation procedures.