Kinetics and mechanisms of the reactions of alkyl radicals with oxygen and with complexes of Co(III), Ru(III), and Ni(III)

• Main Author: Kelley, D.
• Language: unknown
• Published: 2008
• Subjects: 37 INORGANIC; ORGANIC; PHYSICAL AND ANALYTICAL CHEMISTRY; ALKYL RADICALS; CHEMICAL REACTIONS; COBALT COMPLEXES; ETHYL RADICALS; NICKEL COMPLEXES; RUTHENIUM COMPLEXES; ACETONITRILE; BROMINE COMPOUNDS; CHEMICAL REACTION KINETICS; CHEMICAL REACTION YIELD; CHLORINE COMPOUNDS; IRIDIUM CHLORIDES; OXYGEN; PHOTOLYSIS; THIOCYANATES; ANTITHYROID DRUGS; CARBONIC ACID DERIVATIVES; CHLORIDES; COMPLEXES; DECOMPOSITION; DRUGS; ELEMENTS; HALIDES; HALOGEN COMPOUNDS; HORMONE ANTAGONISTS; IRIDIUM COMPOUNDS; KINETICS; NITRILES; NONMETALS; ORGANIC COMPOUNDS; ORGANIC NITROGEN COMPOUNDS; ORGANIC SULFUR COMPOUNDS; PHOTOCHEMICAL REACTIONS; RADICALS; REACTION KINETICS; REFRACTORY METAL COMPOUNDS; TRANSITION ELEMENT COMPLEXES; TRANSITION ELEMENT COMPOUNDS; YIELDS; Carbonic acid
• Online Access: http://www.osti.gov/servlets/purl/6454295; https://www.osti.gov/biblio/6454295; https://doi.org/10.2172/6454295

The kinetics of the reactions of C{sub 2}H{sub 5} radical with Co(NH{sub 3}){sub 5}X{sup 2+}, Ru(NH{sub 3}){sub 5}X{sup 2+}, and Co(dmgH){sub 2} (X) (Y) (X = Br, Cl, N{sub 3}, SCN; Y = H{sub 2}O, CH{sub 3}CN) complexes were studied using laser flash photolysis of ethylcobalt complexes. The kinetics were obtained by the kinetic probe method. Some relative rate constants were also determined by a competition method based on ethyl halide product ratios. The kinetics of colligation reactions of a series of alkyl radicals with {beta}-Ni(cyclam){sup 2+} were studied using flaser flash photolysis of alkylcobalt complexes. Again, the kinetics were obtained by employing the kinetic probe competition method. The kinetics of the unimolecular homolysis of a series of RNi(cyclam)H{sub 2}O{sup 2+} were studied. Activation parameters were obtained for the unimolecular homolysis of C{sub 2}H{sub 5}Ni(cyclam)H{sub 2}O{sup 2+}. Kinetic and thermodynamic data obtained from these reactions were compared with those for the {sigma}-bonded organometallic complexes. The kinetics of the unimolecular homolysis of a series of RNi(cyclam)H{sub 2}O{sup 2+} complexes were studied by monitoring the formation of the oxygen insertion product RO{sub 2}Ni(cyclam)H{sub 2}O{sup 2+}. The higher rate constants for the reactions of alkyl radicals with oxygen in solution, as compared with those measured in the gas phase, were discussed. 30 refs.