title: Hydroxycarbonyl complexes as key intermediates in the base-assisted reduction of ruthenium carbonyls.
abstract: Since the recognition of metal-hydroxycarbonyl (or, metallacarboxylic acid) as a key intermediate in water gas shift (WGS) catalysis, numerous metal complexes incorporating hydroxycarbonyl ligands have been synthesized. In this Perspective, a brief account on the chemistry of metallacarboxylic acid and metallacarboxylate is presented. Special emphasis is placed on the hydroxycarbonyl-bridged dinuclear compounds. The relevance of hydroxycarbonyl complexes in the base-assisted reduction of ruthenium carbonyls is investigated. In particular, Lavigne's synthesis of Roper's catalyst Ru(CO)(2)(PPh(3))(3), triruthenium dodecacarbonyl Ru(3)(CO)(12), and Bera's mechanistic investigation on the preparation of the metal-metal singly bonded diruthenim(I) complex [Ru(2)(CO)(4)(CH(3)CN)(6)](2+) are described in detail. These reactions involve the decarboxylation of a "[Ru(m)(COOH)(n)]" species, followed by the reductive elimination of HX (X = H, Cl or OH), steps akin to WGS catalysis. The prospect of hydroxycarbonyl chemistry in the development of bimetallic catalysis is examined.
authors.affiliation: Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, 208016, India.
authors.forename: Arup
authors.initials: A
authors.lastname: Sinha
authors.forename: Tapas
authors.initials: T
authors.lastname: Ghatak
authors.forename: Jitendra K
authors.initials: JK
authors.lastname: Bera