Photochemical Formation of Free Radicals from Aliphatic Amines as Studied by Electron Spin Resonance

Hadley, Steven G.; Volman, David H.

doi:10.1021/ja00981a002

Cited by 28 publications

(10 citation statements)

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“…Free radical formation from aliphatic amines has been investigated previously by a number of methods. For studies of the solid state, electron spin resonance was used to observe radical species produced by X-rays (3) and y-radiolysis (4-6) in single crystals or by uv photolysis (7,8) in frozen glasses. Optical absorption was used to follow the radicals produced by pulse radiolysis (9)(10)(11)(12) in aqueous solutions that were saturated with N 2 0 to convert ePa,.…”

Section: Andh~-(ch~)-~~h~-(ch~)~-~~h~) Etc Asmentioning

confidence: 99%

“…N-centered radicals were also formed by ultraviolet irradiation of glassy samples of mono-, di-, and trialkyl amines at low temperatures (7,8). However, in the reaction of OH radicals with aliphatic amines in aqueous solution (9)(10)(11)(12)(13)(14)17), H-abstraction from the nitrogen as well as from the carbon adjacent to it occurred in alkaline medium.…”

Section: Andh~-(ch~)-~~h~-(ch~)~-~~h~) Etc Asmentioning

confidence: 99%

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Electron spin resonance of spin-trapped radicals of amines and polyamines. Hydroxyl radical reactions in aqueous solutions and γ-radiolysis in the solid state

Mossoba¹,

Rosenthal²,

Riesz³

1982

Can. J. Chem.

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MAGDI M. MOSSOBA, IONEL ROSENTHAL, and PETER RIESZ. Can. J. Chem. 60, 1493 (1982). The reactions of hydroxyl radicals with methylamine, dimethylamine, trimethylamine, diethylamine, see-butylamine, ethylenediamine, 1,3-diaminopropane, putrescine, cadaverine, 1,7-diaminoheptane, ornithine, spermidine, spermine, agmatine, and arcaine in aqueous solutions have been investigated by spin-trapping and esr. Hydroxyl radicals were generated by the uv photolysis of H,O, and 2-methyl-2-nitrosopropane (MNP) was used as the spin-trap. The effects of ionizing radiation on the same polyamines in the polycrystalline state were also investigated. The free radicals produced by y-radiolysis of these solids at ro0.m temperature in the absence of air were identified by dissolution in aqueous solutions of MNP. The predominant reaction of OH with amines and polyamines below pH 7 was the abstraction of hydrogen atoms from a carbon that is not adjacent to the protonated amino group. For agmatine and arcaine which contain guanidinium groups abstraction occurred from the a-CH. Dimethylamine was oxidized to the dimethylnitroxyl radical by H,O, in the dark. y-Radiolysis of polyamines in the polycrystalline state generated radicals due to H-abstraction from either the a-CH or from a carbon atom in the middle of the alkyl chain. The deamination radical was obtained from ornithine. Faisant appel B la rpe et B I'utilisation de piegeurs de spin, on a itudiC la reaction des radicaux hydroxyles avec des solutions aqueuses des amines suivantes: methylamine, dimethylamine, trimethylamine, diethylamine, see-butylamine, Cthylknediamine, I diamino-1,3 propane, putrescine, cadavtrine, diamino-1,7 heptane, ornithine, spermidine, spermine, agmatine et arcaine. Les

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Section: Andh~-(ch~)-~~h~-(ch~)~-~~h~) Etc Asmentioning

confidence: 99%

Section: Andh~-(ch~)-~~h~-(ch~)~-~~h~) Etc Asmentioning

confidence: 99%

Electron spin resonance of spin-trapped radicals of amines and polyamines. Hydroxyl radical reactions in aqueous solutions and γ-radiolysis in the solid state

Mossoba¹,

Rosenthal²,

Riesz³

1982

Can. J. Chem.

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“…The spectrum of this radical, shows a main septet with a splitting of 28.0 G and an external satellite line (1,2). This spectrum has been interpreted in terms of equal, isotropic, proton and nitrogen splitting constants (1).…”

Section: Methodsmentioning

confidence: 92%

“…The field sweep calibration was carried out by a Mn2+ irradiation in the solid state (1)(2)(3)(4). The low doped sample of MgO (5).…”

mentioning

confidence: 99%

Electron spin resonance study of γ-irradiated ethyleneimine in the solid state

Cordischi¹,

Blasi²

1969

Can. J. Chem.

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The electron spin resonance (e.s.r.) study of the ethyleneimine in polycrystalline and glassy state shows CH,-XH, that the radical \N/ is formed by y-irradiation at 77 O K . The features of the e.s.r. spectrum of this radical are discussed in terms of the isotropic and anisotropic hyperfine coupling constants of the hydrogen and nitrogen nuclei. The effects of bleaching the y-irradiated sample with visible and ultraviolet light are also reported. -and ultraviolet (u-v.) The field sweep calibration was carried out by a Mn2+ irradiation in the solid state (1-4). The low doped sample of MgO (5). melting points of these compounds make single crystal studies difficult. The published spectra Results have been obtained from irradiated polyciysta~-Anhydrous ethyleneirmne frozen at -196 oC line samples. The anisotropic effects give rise to gives an opaque crystalline matrix which after poorly spectra which are generally y-irradiation shows a weak blue color. The jnterpret Only in a product containing about 20% of water gives a few cases are fairly clear spectra obtained.transparent glass with an intense blue color after In the present investigation the of y-irradiation. The e.s,r. spectrum, recorded at which gives a we' ' -196 OC, is practically the same in both cases and spectrum, is reported.does not change from -196 to about -90 "C. ExperimentalEthyleneimine (Fluka reagent) was purified by distillation and dried with a sodium mirror. Ethyleneimine-dl was prepared by exchange of ethyleneimine with D,O. Its isotopic purity, checked by nuclear magnetic resonance, was better than 95 %. The e.s.r. spectra were recorded at 9.2 GHz using a Hilger and Watts Microspin spectrometer with a TED,, cylindrical cavity.The measurements were performed at -196 "C by keeping the sample tubes in a quartz Dewar filled with liquid nitrogen, or at higher temperatures by using a variable nitrogen flow system. 'This work was supported by Consiglio .Nazionale delle Ricerche.

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“…It is part of our systematic investigation on radicals containing one nitrogen atom, such as NH 2 [ 12], H 2 CN [9], (CH 2 )zN, (CH 2 )zNH+, and the cyclic compounds C 3 H 6 N and C 3 H 6 NH + [ 10]. The first investigation on the neutral compound (CH 3 hN was carried out by Hadly and VoJman [ 13] who concluded that the unpaired electron resides in a sp 3 hybrid orbital, based on the large isotropic hfcc's measured for the nitrogen center ( 32 G). Different results were reported by Danen and Kensler [ 14] who observed a far smaller isotropic hfcc ( 14.78 G) for the nitrogen center.…”

Section: Introductionmentioning

confidence: 99%

Theoretical study of the dimethylamino radical (CH3)2N and its protonated cation (CH3)2NH+

1994

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In the present work the dimethylamino radical ( ( CH 3 ) 2 N) and its protonated cation ( ( CH 3 hNH +) are investigated by means of ab initio methods. The geometries of various conformations of both compounds are obtained with UMP2/6·31 G** calculations, while the hyperfine structure and its dependence on the geometry is studied using the MRD-Cl/BK method. The two molecules are compared to study the inftuence of the protonation on geometry and hyperfine structure. The effects of the rotational barriers on the hyperfine structures of (CH 3 hN, (CH 3 CH 2 hN and ( (CH 3 hCHhN will be discussed.

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Photochemical Formation of Free Radicals from Aliphatic Amines as Studied by Electron Spin Resonance

Cited by 28 publications

References 1 publication

Electron spin resonance of spin-trapped radicals of amines and polyamines. Hydroxyl radical reactions in aqueous solutions and γ-radiolysis in the solid state

Electron spin resonance of spin-trapped radicals of amines and polyamines. Hydroxyl radical reactions in aqueous solutions and γ-radiolysis in the solid state

Electron spin resonance study of γ-irradiated ethyleneimine in the solid state

Theoretical study of the dimethylamino radical (CH3)2N and its protonated cation (CH3)2NH+

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