Methyl radical reactions in aqueous solutions. I. Hydrogen abstraction from acetone

1969 ◽  
Vol 73 (12) ◽  
pp. 4406-4409 ◽  
Author(s):  
Issam A. I. Taha ◽  
Robert R. Kuntz
Keyword(s):  
Aqueous Solutions ◽  
Hydrogen Abstraction ◽  
Radical Reactions ◽  
Methyl Radical

Oxidations with lead tetraacetate. III. Oxidations of 2-substituted-1,3-benzodioxoles

1980 ◽  
Vol 33 (7) ◽  
pp. 1553 ◽  
Author(s):  
ER Cole ◽  
G Crank ◽  
HTH Minh
Keyword(s):  
Free Radical ◽  
Hydrogen Abstraction ◽  
Lead Tetraacetate ◽  
Ring Formation ◽  
Radical Reactions ◽  
Initial Attack ◽  
Free Radical Reactions

Oxidation of 2-alkyl- and 2-aryl-1,3-benzodioxoles with lead tetraacetate gives products mainly derived from cleavage of the dioxole ring. Formation of products is suggested to follow initial attack and hydrogen abstraction at the 2-position of the benzodioxole. Subsequent reactions then occur to give the observed products. The processes are seen as free radical reactions.

Morphology and radical reactions of Cu(II) and Co(II) sulfonated phthalocyanines covalently linked to poly(ethyleneamide)

2010 ◽  
Vol 14 (01) ◽  
pp. 69-80 ◽  
Author(s):  
Gustavo T. Ruiz ◽  
Alexander G. Lappin ◽  
Guillermo Ferraudi
Keyword(s):  
Aqueous Solutions ◽  
Redox Reactions ◽  
Radical Reactions ◽  
Stable Bundles ◽  
Carbon Bonds ◽  
Amine Groups ◽  
Covalently Linked ◽  
The Stability ◽  
Sulfonated Phthalocyanines

The tetrasulfonated Cu II( tspc )4-, tspc = 4,4′,4″,4‴-phthalocyaninetetrasulfonate, and the trisulfonated Co II( trspc )3-, trspc = n , n ′, n ″-phthalocyanine-trisulfonate and n, n′ and n″ indicate the sulfonated positions of the various isomers, were covalently linked to a polyethyleneimine, M n ~ 10000 and M w ~ 25000, backbone. A fraction of the amine groups in a strand was converted to Cu II pc (- SO 3)3(- SO 2 N <)\3- or Co II pc (- SO 3)2(- SO 2 N <)\2- pendants and the remaining were acetylated. Strands of the polymers, poly(K3CuIItspc) and poly(K2CoIItrspc) , formed spherical bundles with diameters ~1000 nm for poly(K3CuIItspc) and ~100 nm for poly(K2CoIItrspc) . The stability of the bundles is metal-dependent. Poly(K2CoIItrspc) forms the most stable bundles with respect to hydrolytic and redox reactions. ESR and optical spectroscopies as well as reactions of the pendants with pulse radiolytically generated radicals, namely e - sol , C•H2OH, (CH3)2COHC•H2 , CO 2•-, N 3• and SO 4•-, revealed a distribution of pendants between isolated and aggregated forms in a bundle. The reduction of the Cu(II) to Cu(I) in aqueous solutions of the poly(K3CuIItspc) was associated with pendants present in a mostly hydrophobic environment. Unstable phthalocyanine pendants with CoIII -carbon bonds are formed when CoIIpc(-SO3)2(-SO2N<)\2- reacted with C -centered radicals, ( CH3)2COHC•H2 and C•H2OH . The species with CoIII -carbon bonds were precursors to the formation of CoIpc(-SO3)2(-SO2N<)\3- pendants. The redox reactions of the pendants in these polymers are compared with those of K4CuIItspc and K3CoIItrspc .

Individual rate constants of methyl radical reactions in the pyrolysis of dimethyl ether

1977 ◽  
Vol 55 (23) ◽  
pp. 4128-4134 ◽  
Author(s):  
Andrew M. Held ◽  
Kim C. Manthorne ◽  
Philip D. Pacey ◽  
Howard P. Reinholdt
Keyword(s):  
Dimethyl Ether ◽  
Rate Constants ◽  
Flow System ◽  
Average Concentration ◽  
Radical Reactions ◽  
Methyl Radical ◽  
Warm Up ◽  
Secondary Reactions ◽  
Ultraviolet Absorption Spectroscopy ◽  
Individual Rate

Dimethyl ether was pyrolyzed in a flow system at 10 to 80 Torr and 1005 K. The average concentration of CH3 radicals in the reactor was measured by ultraviolet absorption spectroscopy. Product yields were measured by gas chromatography. The system was simulated using a computer program, taking into account the warm-up of the entering gas and the occurrence of secondary reactions. Rate constants were varied to find values consistent with experimental observations. The limiting, high pressure rate constant for the recombination of CH3 was estimated to be 1010.5 ± 0.5ℓ mol−1 s−1. Estimated rate constants for the reactions[Formula: see text]were 107.12 ± 0.2ℓ mol−1 s−1 and 107.5 ± 0.4ℓ mol−1 s−1, respectively.

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