Synthesis and reductive chemistry of bimetallic and trimetallic rare-earth metallocene hydrides with (C5H4SiMe3)1− ligands

Authors

Megan T. Dumas, University of California, Irvine
Guo P. Chen, University of California, Irvine
Jasper Y. Hu, University of California, Irvine
Mitchell A. Nascimento, University of Windsor
Jeremy M. Rawson, University of WindsorFollow
Joseph W. Ziller, University of California, Irvine
Filipp Furche, University of California, Irvine
William J. Evans, University of California, Irvine

Document Type

Article

Publication Date

11-2017

Publication Title

Journal of Organometallic Chemistry

Volume

849-850

Issue

1

First Page

38

Keywords

Lanthanide, Cyclopentadienyl, Hydride, Reduction, Polymetallic

Last Page

47

Abstract

The reductive chemistry of [Cp'₂Ln(μ–H)(THF)_x]_y [Ln = Y, Dy, Tb; Cp' = (C₅H₄SiMe₃)¹⁻; x = 2, 0 and y = 2, 3] was examined to determine if these hydrides would be viable precursors for 4fⁿ5d¹ Ln²⁺ ions that could form 5d¹-5d¹ metal–metal bonded complexes. The hydrides were prepared by reaction of the chlorides, [Cp'₂Ln(μ–Cl)]₂, 1-Ln, with allylmagnesium chloride to form the allyl complexes, [Cp'₂Y(η³–C₃H₅)(THF)], 2-Ln, which were hydrogenolyzed. The solvent-free reaction of solid 2-Ln with 60 psi of H₂ gas in a Fischer-Porter apparatus produced, in the Y case, the trimetallic species, [Cp'₂Y(μ–H)]₃, 3-Y, and in the Dy and Tb cases, the bimetallic complexes [Cp'₂Ln(μ–H)(THF)]₂, 4-Ln (Ln = Dy, Tb). The latter complexes could be converted to 3-Dy and 3-Tb by heating under vacuum. Isopiestic data indicate that 3-Y solvates to 4-Y in THF. Reductions of 4-Y, 4-Dy, and 4-Tb with KC₈ in the presence of a chelate such as 2.2.2-cryptand or 18-crown-6 all gave reaction products with intense dark colors characteristic of Ln²⁺ ions. In the yttrium case, with either chelating agent, the dark green product gives a rhombic EPR spectrum (g₁ = 2.01, g₂ = 1.99, g₃ = 1.98, A = 24.1 G) at 77 K. However, the only crystallographically-characterizable products obtainable from these solutions were Ln³⁺polyhydride anion complexes of composition, [K(chelate)]{[Cp'₂Ln(μ–H)]₃(μ–H)}.

DOI

10.1016/j.jorganchem.2017.05.057

Funding Reference Number

NSERC

Comments

Dedicated to Professor Rick Adams for his extensive and continuous contributions to inorganic and organometallic chemistry and the advancement of polymetallic cluster chemistry.

This is an accepted manuscript. The version of record is available at https://doi.org/10.1016/j.jorganchem.2017.05.057

Creative Commons License

This work is licensed under a Creative Commons Attribution-No Derivative Works 4.0 International License.

Recommended Citation

Dumas, Megan T.; Chen, Guo P.; Hu, Jasper Y.; Nascimento, Mitchell A.; Rawson, Jeremy M.; Ziller, Joseph W.; Furche, Filipp; and Evans, William J.. (2017). Synthesis and reductive chemistry of bimetallic and trimetallic rare-earth metallocene hydrides with (C5H4SiMe3)1− ligands. Journal of Organometallic Chemistry, 849-850 (1), 38-47.
https://scholar.uwindsor.ca/chemistrybiochemistrypub/90