17857-24-8Relevant articles and documents
Condensation of mononuclear [HM(CO)4]- to trinuclear [HM3(CO)11]- metal hydrido carbonyl anions (M = Fe, Ru, Os) under protic and water gas shift conditions
Bricker, Jeffery C.,Bhattacharyya, Nripendra,Shore, Sheldon G.
, p. 201 - 204 (1984)
Stoichiometries and conditions for the condensation of [HM(CO)4]- to [HM3(CO)11]- for M = Fe, Ru, and Os have been determined. Under protic and water gas shift conditions, the [HRu(CO)4]- anion is rapidly converted to the trinuclear cluster anion [HRu3(CO)11-]. In protic media the [HFe(CO)4]- anion condenses to [HFe3(CO)11]-, but at a markedly slower rate. Under water gas shift conditions, [HFe(CO)4]- does not form ([HFe3(CO)11]-. Instead, within a period of 24 h a catalytically inactive material is formed. In protic media [HOs(CO)4]- slowly forms [HOs3(CO)11]-. The [HOs(CO)4]- anion is more active than [HOs3(CO)11]- for the catalysis of the water gas shift reaction.
Reaction of potassium tetracarbonylhydridoferrate with aryl halides: mechanistic study and extension to the catalytic carbonylation of iodobenzene by a bimetallic Fe(CO)5-Co2(CO)8 system
Brunet,de Montauzon,Taillefer
, p. 341 - 346 (2008/10/08)
Potassium tetracarbonylhydriodoferrate, KHFe(CO)4, reacts with aryl iodides in wet methanol to yield the corresponding arenes. This reaction is catalytic under carbon monoxide (1 atm) in the presence of an excess of base. Mechanistic investigations, both by IR analysis and by electrochemical experiments, show that the reaction involves an electron transfer from HFe(CO)4- to the aryl halide to generate the corresponding radical anion. The resulting aryl radical either abstracts an hydrogen atom from potassium methoxide of combines with the [HFe(CO)4] radical species to form ArFe(H)(CO)4, which yields ArH by reductive elimination. The catalytic carbonylation of iodobenzene to benzoic acid can be performed under very mild conditions by a bimetallic system, viz. HFe(CO)4--Co(CO)4-. The observed synergetic effect is believed to involve first an electron transfer from HFe(CO)4- to iodobenzene and generation of a phenyl radical, followed by reaction with Co(CO)4-, which acts as the actual carbonylation catalyst. In agreement with these hypotheses, the carbonylation of bromobenzene, which on its own is unreaction under these conditions, can be promoted by the presence of iodobenzene.
