摘要：

Crystallization of lanthanide trichlorides from neat {eta}-caprolactone (C{sub 6}H{sub 10}O{sub 2}) and caprolactone/THF mixtures has revealed a much more diverse structural chemistry for solvated lanthanide trichloride complexes than had previously been observed. As the metal is varied, different products preferentially crystallize under the same conditions to give a series of complexes which do not vary smoothly in composition as a function of radial size. The following compounds, in order of increasing radial size of the metal, have been structurally characterized: YbCl{sub 3}(C{sub 6}H{sub 10}O{sub 2})- (THF){sub 2}, 1; YCl{sub 3}(C{sub 6}H{sub 10}O{sub 2}){sub 3}, 2; [TbCl{sub 4}(THF){sub 2}]{sup -}[TbCl{sub 2}(THF){sub 5}]{sup +}, 3; [Cl{sub 3}Sm({mu}-Cl){sub 3}]{sup 3-}[Sm(C{sub 6}H{sub 10}O{sub 2}){sub 8}]{sup 3+}, 4;[Cl{sub 3}Nd({mu}-Cl){sub 3}NdCl{sub 3}]{sup 3-}[Nd(C{sup 6}H{sub 10}O{sub 2}){sub 8}]{sup 3+}, 5. In the course of these studies, the polymeric halides [NdCl({mu}-Cl){sub 2-}(THF){sub 2}]{sub n}, 6, and [CeCl({mu}-Cl){sub 2}(THF){sub 2}]{sub n}, 7, were also identified by X-ray crystallography. Although both 1 and 2 have octahedral geometries, they differ in the amount of caprolactone present and the fact that 1 is facial while 2 is meridional. The ion pair system 3 contains a six-coordinate anion with a trans octahedral geometry and a seven-coordinate cation with axial chloride ligands in a pentagonal bipyramidal structure. Complexes 4 and 5 contain bimetallic trianions devoid of caprolactone which adopt a face-sharing bioctahedral geometry. The eight-coordinate cations in 4 and 5 contain no chloride ligands and adopt a square antiprismatic geometry. Isostructure 6 and 7 contain seven-coordinate pentagonal bipyramidal metal centers surrounded by four bridging chloride atoms, one terminal chloride, and two terminal THF ligands.

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