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Monodentate Alkoxy/Aryloxy Anchored Yttrium Dihydrides; Anticipated Outcomes and Surprises.
Yang, Yi; Del Rosal, Iker; Ferguson, Michael J; McDonald, Robert; Maron, Laurent; Takats, Josef.
Afiliação
  • Yang Y; Department of Chemistry, University of Alberta, Edmonton, AB T6G2G2, Canada.
  • Del Rosal I; Université de Toulouse, CNRS, INSA, UPS, UMR 5215, LPCNO, 135 avenue de Rangueil, F-31077 Toulouse, France.
  • Ferguson MJ; Department of Chemistry, University of Alberta, Edmonton, AB T6G2G2, Canada.
  • McDonald R; Department of Chemistry, University of Alberta, Edmonton, AB T6G2G2, Canada.
  • Maron L; Université de Toulouse, CNRS, INSA, UPS, UMR 5215, LPCNO, 135 avenue de Rangueil, F-31077 Toulouse, France.
  • Takats J; Department of Chemistry, University of Alberta, Edmonton, AB T6G2G2, Canada.
Inorg Chem ; 62(28): 11179-11187, 2023 Jul 17.
Article em En | MEDLINE | ID: mdl-37410952
The synthesis, characterization, and solid-state structure of bulky alkoxy- and aryloxy-supported yttrium polynuclear hydrides are reported. Hydrogenolysis of the supertrityl alkoxy anchored yttrium dialkyl, Y(OTr*)(CH2SiMe3)2(THF)2 (1) (Tr* = tris(3,5-di-tert-butylphenyl)methyl), resulted in the clean conversion to the tetranuclear dihydride, [Y(OTr*)H2(THF)]4 (1a). X-ray analysis revealed a highly symmetrical structure (4̅ site symmetry) with the four Y atoms located on the corners of a compressed tetrahedron, each bonded to an OTr* and tetrahydrofuran (THF) ligand and the cluster held together by four face-capping, µ3-H, and four edge-bridging, µ2-H, hydrides. DFT calculations on the full system with and without THF, but also on model systems, clearly show that the structural preference for complex 1a is controlled by the presence and coordination of THF molecules. Contrary to the exclusive formation of the tetranuclear dihydride, hydrogenolysis of the bulky aryloxy yttrium dialkyl, Y(OAr*)(CH2SiMe3)2(THF)2 (2) (Ar* = 3,5-di-tert-butylphenyl) gave a mixture of the analogous tetranuclear 2a and trinuclear, [Y3(OAr*)4H5(THF)4], polyhydride, 2b. Similar results, i.e., a mixture of tetra-/tri-nuclear products, were obtained from hydrogenolysis of the even bulkier Y(OArAd2,Me)(CH2SiMe3)2(THF)2 compound. Experimental conditions were established to optimize the production of either the tetra- or trinuclear products. X-ray structure of 2b revealed a triangular array of three yttrium atoms with two face-capping µ3-H and three edge-bridging µ2-H hydrides, with one yttrium bonded to two aryloxy ligands while the other two have a complement of one aryloxy and two THF ligands; the solid-state structure is close to being C2 symmetric, with the C2 axis running through the unique Y and unique µ2-H hydride. As opposed to 2a, which shows distinct 1H NMR resonances for µ3/ µ2-H (δ = 5.83/6.35 ppm, respectively), no hydride signals for 2b were observed at room temperature, indicating hydride exchange on the NMR time scale. Their presence and assignment were secured at -40 °C from 1H SST (spin saturation) experiment.

Texto completo: 1 Base de dados: MEDLINE Idioma: En Ano de publicação: 2023 Tipo de documento: Article

Texto completo: 1 Base de dados: MEDLINE Idioma: En Ano de publicação: 2023 Tipo de documento: Article