Issue 17, 2017

Synthesis and characterisation of tetranuclear ruthenium polyhydrido clusters with pseudo-tetrahedral geometry

Abstract

Dicationic tetranuclear ruthenium octahydride [(Cp*Ru)4H8]2+ (5) with tetrahedral geometry was obtained by reaction of dinuclear ruthenium tetrahydride (Cp*Ru)2(μ-H)4 (1) with an excess of Brønsted acids, such as HBF4·OEt2, in toluene. Monocationic tetraruthenium heptahydride [(Cp*Ru)4H7]+ (7) was obtained by dropwise addition of a diluted acid to a rigorously stirred solution of 1 at ambient temperature. Dication 5 was converted into monocationic heptahydrido complex 7 in high yield by treatment with sodium methoxide or sodium hydride. The direct conversion of 5 into neutral hexahydrido complex (Cp*Ru)4H6 (8) was achieved in a highly efficient manner by treating 5 with LiAlH4 in tetrahydrofuran (THF). The conversion of 5 into 8 was reversible, and the addition of a Brønsted acid to 8 gave 5via the formation of 7 as an intermediate. Tetranuclear complex 8 was directly obtained from 1 by heating it in THF at 70 °C. Complex 8′ and tetraruthenium tetrahydride (CpEtRu)4H4 (10′), where 8′ and 10′ possessed η5-C5EtMe4 ligands instead of Cp* ligands, were mutually related by the elimination/addition of dihydrogen. The structures of 5, 7, 8, and 10′ were determined by X-ray diffraction, and the Ru4 core structure and the coordination mode of hydrido ligands were discussed based on density functional theory (DFT) calculations for model compounds where the methyl groups of Cp* ligands were replaced with hydrogen atoms.

Graphical abstract: Synthesis and characterisation of tetranuclear ruthenium polyhydrido clusters with pseudo-tetrahedral geometry

Supplementary files

Article information

Article type
Paper
Submitted
30 Nov. 2016
Accepted
09 Janv. 2017
First published
10 Janv. 2017

Dalton Trans., 2017,46, 5631-5643

Synthesis and characterisation of tetranuclear ruthenium polyhydrido clusters with pseudo-tetrahedral geometry

H. Kameo, Y. Ito, R. Shimogawa, A. Koizumi, H. Chikamori, J. Fujimoto, H. Suzuki and T. Takao, Dalton Trans., 2017, 46, 5631 DOI: 10.1039/C6DT04523E

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements