Reactivity of 1.4-benzoquinone with trinuclear ruthenium and osmium clusters: Facile hydrogenation of the quinoid fragment

• Published in: Journal of organometallic chemistry Vol. 812; pp. 207 - 216
• Main Authors: Pelayo-Vázquez, J. Benito, González-Bravo, Felipe J., Leyva, Marco A., Rosales-Hoz, María J.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15-06-2016
• Subjects: Benzoquinone; Hydroquinone; Osmium clusters; Ruthenium clusters; Hydroquinone; Benzoquinone; Ruthenium clusters; Osmium clusters
• ISSN: 0022-328X; 1872-8561
• DOI: 10.1016/j.jorganchem.2015.12.015

The reaction of [H2Os3(CO)10] with 1,4-benzoquinone yields initially a complex where the quinone bonds to the metal framework, both through a carbon atom of the ring and through an oxygen atom. Evidence suggests that this complex is a kinetic product which then transforms into complexes in which the quinone bonds through the oxygen atom. In one case, an oxygen atom of a hydroquinone moiety, bridges one of the metal–metal bonds, and in the other, a benzoquinone group acts, coordinated through the oxygen atoms, as a bridge between two trinuclear fragments. Similar products are obtained from the reaction of [Ru3(CO)12] with the same quinone in a hydrogen atmosphere although the presence of hydrogen leads to a partial hydrogenation of the benzoquinone ring. The reaction of [Os3(CO)10(MeCN)2] with the same quinone, formed a compound where the quinone is coordinate η2 through one of the double bonds of the ring to one of the osmium atoms. The products were characterized spectroscopically and; for four of the compounds; by X-ray crystallography.
The reactions of 1,4-benzoquinone with [Ru3(CO)12] in the presence of hydrogen, and with [H2Os3(CO)10] gave products with a hydoquinone ligand is coordinated through one or both of the oxygen atoms to a metal–metal bond forming a bridge. Other products show partial hydrogenation of the aromatic ring accompanied by coordination through oxygen and carbon atoms. Spectroscopic and structural characterization of the products are presented. [Display omitted]
•Reaction of 1,4-benzoquinone with [Ru3(CO)12] under a hydrogen atmosphere with partial hydrogenation of the quinone.•In the reaction of [H2Os3(CO)10] with 1,4-benzoquinone, the hydride groups induce hydrogenation of the quinone.•Coordination of the quinone fragments to the metal clusters through the oxygen atoms is favored.