Document Type

Article

Publication Date

11-2017

Publication Title

Journal of Organometallic Chemistry

Volume

849-850

Issue

1

First Page

38

Last Page

47

DOI

10.1016/j.jorganchem.2017.05.057

Keywords

Lanthanide, Cyclopentadienyl, Hydride, Reduction, Polymetallic

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)}.

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

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

Available for download on Friday, November 02, 2018

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