Structural Diversity in Solvated Lanthanide Halide Complexes

Abstract

Crystallization of lanthanide trichlorides from neat e-caprolactone (CeHioCy 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:In the course of these studies, the polymeric halides [NdCl(«-Cl)2-(THF)2]", 6, and [CeCl(M-Cl)2(THF)2]", 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 eightcoordinate cations in 4 and 5 contain no chloride ligands and adopt a square antiprismatic geometry. Isostructural 6 and 7 contain seven-coordinate pentagonal bipyramidal metal centers surrounded by four bridging chloride atoms, one terminal chloride, and two terminal THF ligands. YbCl3(C6Hio02)(THF)2, 1, crystallized from e-caprolactone/THF in space group P2\tn [C^,; No. 14] with a = 11.580(2) Á, b = 12.802(3) Á, c = 13.532(3) Á, ß = 103.462(15)°, V = 1951.0(7) Á3, and DcaJcd = 1.831 Mg/m3 for Z = 4. Least-squares refinement of the model based on 3894 reflections (|F0| > 3.0ct(|Fo|)) converged to RF = 3.5%. YCl3(C6Hio02)3, 2, crystallized from both e-caprolactone/THF and neat e-caprolactone in the space group PI with a = 10.083(1) k,b = 11.706-(1) k,c= 11.702(1) Á, a = 60.071(7)°, ß = 81.274(9)°, = 75.741(8)°, V= 1159.4(2) Á3, and Dcalcd = 1.540 Mg/m3 for Z = 2. Least-squares refinement of the model based on 4846 observed reflections (|F0| > 2.0ct(|Fo|)) converged to RF = 4.0%. [TbCL(THF)2]_[TbCl2(THF)5]+, 3, crystallized from e-caprolactone/THF in the space group C2/c [Cf2h; No. 15] with a = 12.401(2) Á, b = 11.420(2) k, c = 27.413(3) Á, ß = 91.100(11)°, V = 3881.4(9) Á3, and Dcaicd = 1.772 Mg/m3 for Z = 8. Least-squares refinement of the model based on 3936 reflections (|F0| > 3.0ct(|Fo|)) converged to RF -3.4%. [Cl3Sm(n-Cl)3SmCl3]3~[Sm(C6Hio02)8]3+, 4, was found to be isomorphous with 5 by a unit cell determination. [Cl3Nd(M-Cl)3NdCl3]3-[Nd(C6Hio02)s]3+, 5, crystallized from both e-caprolactone/THF and neat e-caprolactone in the space group Fife [C^; No. 14] with a = 19.661(4) Á, b = 11.775(4) Á, c = 28.141(5) Á, ß = 96.615(16)°, V = 6471(3) Á3, and Dcalcd = 1.709 Mg/m3 for Z = 4. Least-squares refinement of the model based on 6823 reflections (|F0| > 3.0a(|Fo|)) converged to RF = 5.5%. [NdCl(n-Cl)2(THF)2]", 6, crystallized from a solution of benzophenone in ...

Lanthanide chloride complexes of amine-bis(phenolate) ligands and their reactivity in the ring-opening polymerization of ε-caprolactone

“…27 Samarium tris(phenolate) complexes have recently been reported as initiators for e-CL ROP and their mechanism studied in some detail. 28 It was proposed that e-CL insertion occurs at all three Sm-O bonds and although in Scheme 2 insertion is only shown into one Ln-O bond, it may well be occuring at both reactive bond sites.…”

Bis(pyridine)difluoroboron, tris(pyridine)fluoroboron, and other (pyridine)haloboron cations. A systematic NMR study

“…NMR, supplemented by FAB, is powerful in identifying haloboron cations and is useful in clarifying situations in which either ionic or covalent isomers (or both together) may be present. It should be kept in mind that unexpected ionic structures can be generated from neutral precursors (30). There have recently been several reports of replacement of a halide ion by a neutral ligand to give a cationic complex (31).…”

Highly luminescent lanthanide complexes sensitised by tertiary amide-linked carbostyril antennae

“…23,[26][27][28] Carbostyrils (quinolin-2(1H)-ones) are among the most widely used antennae for the sensitisation of Eu and Tb, of which the most commonly used one is cs124 (Scheme 1, 2a). [29][30][31][32][33][34][35][36][37] Some are even effective for Sm and Dy, 38 as well as the near infrared (NIR) emitting Yb and Nd. 39 A variety of substituted carbostyrils have been reported (Fig.…”