Nucleophilic activation of coordinated carbon monoxide. Reaction of tungsten hexacarbonyl with methoxide salts

• Published in: Inorganic chemistry Vol. 32; no. 12; pp. 2651 - 2656
• Main Authors: Bates, Allan, Muraoka, Mark T, Trautman, Raymond J
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.06.1993
• Subjects: 400201 - Chemical & Physicochemical Properties; ALKOXIDES; CARBON COMPOUNDS; CARBON MONOXIDE; CARBON OXIDES; CARBONYLS; CATALYTIC EFFECTS; CHALCOGENIDES; CHEMICAL ACTIVATION; CHEMICAL REACTION KINETICS; Chemistry; COMPLEXES; EQUILIBRIUM; Exact sciences and technology; FLUIDS; FUEL GAS; FUELS; GAS FUELS; GASES; Inorganic chemistry and origins of life; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; INTERMEDIATE BTU GAS; KINETICS; Kinetics and mechanism of reactions; ORGANIC COMPOUNDS; ORGANOMETALLIC COMPOUNDS; OXIDES; OXYGEN COMPOUNDS; REACTION KINETICS; TRANSITION ELEMENT COMPLEXES; TUNGSTEN COMPLEXES; WATER GAS; Chemical equilibrium; Alkoxy complex; Nucleophilic reaction; Organic ligand; Reaction mechanism; Transition metal Carbonyl Complexes; Anionic complex; Rate constant; Tungsten Carbonyl Complexes; Quaternary phosphonium compound
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/ic00064a014

Kinetics studies of the reactions of [Na[sup +]][OCH[sub 3][minus]] and [((C[sub 6]H[sub 5])[sub 3]P)[sub 2]N[sup +]][OCH[sub 3][minus]] with W(CO)[sub 6] are reported. The preparation of acetonitrile solutions of ((C[sub 6]H[sub 5])[sub 3]P)[sub 2]NOCH[sub 3], a convenient source of solubilized methoxide ion in aprotic media, is described. Second-order rate constants (730 [plus minus] 130 M[sup [minus]1] and 743 [plus minus] 61 M[sup [minus]1] s[sup [minus]1]) and equilibrium constants (3200 [plus minus] 300 M[sup [minus]1] and 1400 [plus minus] 200 M[sup [minus]1]) for the formation of the methoxycarbonyl complexes [M[sup +]][W(CO)[sub 5]CO[sub 2]CH[sub 3][minus]] (M[sup +] = Na[sup +] and ((C[sub 6]H[sub 5])[sub 3]P)[sub 2]N[sup +], respectively) at 25[degrees]C are several orders of magnitude lower than those reported for the formation of group VIII methoxycarbonyl complexes. Addition of trace quantities of water to THF/CH[sub 3]OH solutions of [Na[sup +]][W(CO)[sub 5]CO[sub 2]CH[sub 3][minus]] surprisingly resulted in the formation of W(CO)[sub 6] and not the expected metal hydride HW(CO)[sub 5][minus]. These observations are consistent with the previously reported variation in catalytic activity of group VI and VIII metal carbonyl compounds for the water gas shift reaction.