Spin trapping azidyl (N3•), cyanatyl (OCN•), cyanyl (•CN) radicals, and chlorine atom (Cl•)

1980 ◽  
Vol 58 (15) ◽  
pp. 1596-1598 ◽  
Author(s):  
Edward G. Janzen ◽  
Henry J. Stronks ◽  
Dale E. Nutter Jr. ◽  
Edward R. Davis ◽  
Henry N. Blount ◽  
...  
Keyword(s):  
Chlorine Atom ◽  
Hydroxyl Radicals ◽  
Spin Trapping ◽  
Chlorine Atoms ◽  
Tert Butyl ◽  
Cn Radicals

Azidyl, cyanatyl, and cyanyl radicals and chlorine atoms have been detected by spin trapping using α-phenyl N-tert-butyl nitrone (PBN) in the monoelectronic electrooxidations of azide, cyanate, cyanide, and chloride. Azidyl and cyanatyl radicals were also detected with PBN in the persulfate oxidations of azide and cyanate. Azidyl radicals could be detected in the reaction of azide with hydroxyl radicals in the presence of PBN.

Atmospheric chemistry of di-tert-butyl ether: Rates and products of the reactions with chlorine atoms, hydroxyl radicals, and nitrate radicals

1996 ◽  
Vol 28 (4) ◽  
pp. 299-306 ◽  
Author(s):  
Sarka Langer ◽  
Evert Ljungstr�m ◽  
Ingvar W�ngberg ◽  
Timothy J. Wallington ◽  
Michael D. Hurley ◽  
...  
Keyword(s):  
Hydroxyl Radicals ◽  
Atmospheric Chemistry ◽  
Butyl Ether ◽  
Chlorine Atoms ◽  
Tert Butyl ◽  
Nitrate Radicals

On the spin trapping of chlorine atoms. Competition from chloride ions

1991 ◽  
Vol 69 (7) ◽  
pp. 1131-1133 ◽  
Author(s):  
Detlef Rehorek ◽  
Edward G. Janzen ◽  
Yashige Kotake
Keyword(s):  
Key Words ◽  
Epr Spectroscopy ◽  
Spin Trapping ◽  
Adduct Formation ◽  
Chloride Ions ◽  
Spin Adduct ◽  
Phenyl Radicals ◽  
Chlorine Atoms ◽  
Tert Butyl ◽  
Epr Spin Trapping

Chlorine atoms generated by photolysis of hexachloroethane add to C-phenyl-N-tert-butyl nitrone (PBN) to form persistent spin adducts that are readily detectable by EPR spectroscopy. The presence of chloride ions reduces spin adduct formation competitively. Chlorine atoms also react with tetraphenylarsenium ions to liberate phenyl radicals by radical replacement. Key words: EPR, spin trapping, C-phenyl-N-tert-butyl nitrone, PBN, photolysis, chlorine atoms, tetraphenylarsenium ion, hexachloroethane.

Enhancement of hydroxyl radical generation by phenols and their reaction intermediates during ozonation

1998 ◽  
Vol 38 (6) ◽  
pp. 147-154 ◽  
Author(s):  
Hideo Utsumi ◽  
Sang-Kuk Han ◽  
Kazuhiro Ichikawa
Keyword(s):  
Hydroxyl Radical ◽  
Hydroxyl Radicals ◽  
Spin Trapping ◽  
Active Species ◽  
Generation Rate ◽  
Peak Height Ratio ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Phenol Derivatives ◽  
Semiquinone Radicals

Generation of hydroxyl radicals, one of the major active species in ozonation of water was directly observed with a spin-trapping/electron spin resonance (ESR) technique using 5,5-dimethyl-1-pyrrolineN-oxide (DMPO) as a spin-trapping reagent. Hydroxyl radical were trapped with DMPO as a stable radical, DMPO-OH. Eighty μM of ozone produced 1.08 X 10-6M of DMPO-OH, indicating that 1.4% of •OH is trapped with DMPO. Generation rate of DMPO-OH was determined by ESR/stopped-flow measurement. Phenol derivatives increased the amount and generation rate of DMPO-OH, indicating that phenol derivatives enhance •OH generation during ozonation of water. Ozonation of 2,3-, 2,5-, 2,6-dichlorophenol gave an ESR spectra of triplet lines whose peak height ratio were 1:2:1. ESR parameters of the triplet lines agreed with those of the corresponding dichloro-psemiquinone radical. Ozonation of 2,4,5- and 2,4,6-trichlorophenol gave the same spectra as those of 2,5- and 2,6-dichlorophenol, respectively, indicating that a chlorine group in p-position is substituted with a hydroxy group during ozonation. Amounts of the radical increased in an ozone-concentration dependent manner and were inhibited by addition of hydroxyl radical scavengers. These results suggest that p-semiquinone radicals are generated from the chlorophenols by hydroxyl radicals during ozonation. The p-semiquinone radicals were at least partly responsible for enhancements of DMPO-OH generation.

Cyclisierung von Di(tert-butyl-methyl)ketazin zu 1,2-Diaza-3-bora- und 1,2-Diaza-3-sila-cyclopent-5-enen / Cyclization of Di(tert-butyl-methyl)ketazine to 1,2-Diaza-3-bora- and 1,2-Diaza-3-sila-cyclopent-5-enes

2006 ◽  
Vol 61 (10) ◽  
pp. 1261-1274 ◽  
Author(s):  
Florian Armbruster ◽  
Nina Armbruster ◽  
Uwe Klingebiel ◽  
Mathias Noltemeyer ◽  
Stefan Schmatz
Keyword(s):  
Crystal Structures ◽  
Quantum Chemical Calculations ◽  
Chlorine Atom ◽  
Quantum Chemical ◽  
Membered Ring ◽  
Substitution Product ◽  
Tert Butyl ◽  
Isomeric Structures

The results of quantum chemical calculations on lithium ketazides suggest mainly four isomeric structures with different modes of lithium coordination (A-D). A monolithium ketazide thf-adduct (1) was isolated supporting the results of the quantum chemical calculations. In reactions of the lithiated di(tert-butyl-methyl)ketazine with BCl3 and Cl2BPh, 1,2-aza-azonia-3-borata-cyclopent-5-enes (2, 3) were isolated. Substitution of a chlorine atom of 2 and 3 with t-BuLi leads to the formation of derivatives 4 and 5. HCl elimination from 2 with Et3N gives - via a diazaboracyclopentene (6) - a bicyclus 7. In the reaction of the dilithiated ketazine with F2BN(SiMe3)2, the diaza-boracyclopentene 8 is obtained while with Cl4Si, F3SiN(SiMe3)2, and Cl2SiMe2 the diazasilacyclopentenes 9 - 11 are generated. SiF4 reacts with the dilithium ketazide to give a spirocyclus (12). The monolithium ketazide and Cl2SiMe2 react at 30 °C to give a four-membered ring isomer of the substitution product which is formed via a 1,3-chlorine shift from silicon to carbon (13). A tetrameric silanolate was isolated as a by-product in this reaction. It gives evidence for the structure of lithium ketazide A. Crystal structures of 5, 7, 10, and 14 are reported.

Three new staphylonuclear chloromolybdates : K6Mo3Cl12, (NH4)7Mo3Cl13,H2O, and Cs6Mo4Cl16

1965 ◽  
Vol 18 (3) ◽  
pp. 271 ◽  
Author(s):  
IR Anderson ◽  
JC Sheldon
Keyword(s):  
Solid State ◽  
Hydrochloric Acid ◽  
Absorption Spectra ◽  
Oxidation State ◽  
Chlorine Atom ◽  
Reducing Agents ◽  
Ammonium Salts ◽  
Chlorine Atoms ◽  
Regular Triangle ◽  
New Compounds

The new compounds, K6Mo3IICl12; (NH4)7Mo3IICl13.H2O; and Cs6Mo4Cl16 (containing molybdenum in oxidation state +2.5) have been precipitated by the appropriate cation from solutions of molybdenum(II) acetate in 12M hydrochloric acid. The absorption spectra of potassium and ammonium salts are similar in the solid state and solution. Since the compounds are strong reducing agents and short-lived in solution, their formulation as a staphylonuclear (i.e. metal-clustered) trimer or tetramer rests on their diamagnetism, stoicheiometry, and spectral similarities. It is proposed that the chloromolybdates adopt entirely novel, compact polymers by stacking the chlorine atoms into "close packed" layers. The Mo3Cl13 group consists of two layers of chlorine atoms (seven and six) generating three octahedral locations for the molybdenum atoms at the corners of a regular triangle. The Mo3Cl12 group is similar but deficient in one chlorine atom. The Mo4Cl16 group is related to Mo3Cl13 and consists of three layers of chlorine atoms (seven, six, and three) providing four octahedral locations for the molybdenum atoms at the corners of a tetrahedron.

Solvent effects on the nitrogen and β-hydrogen hyperfine splitting constants of aminoxyl radicals obtained in spin trapping experiments

1982 ◽  
Vol 60 (21) ◽  
pp. 2725-2733 ◽  
Author(s):  
Edward G. Janzen ◽  
Gregory A. Coulter ◽  
Uwe M. Oehler ◽  
John P. Bergsma
Keyword(s):  
Linear Relationship ◽  
Solvent Effects ◽  
Hyperfine Splitting ◽  
Spin Trapping ◽  
Tert Butyl ◽  
Aminoxyl Radicals ◽  
Structural Significance

The nitrogen and β-hydrogen hyperfine splitting constants (hfsc) for phenyl, 4-nitrophenyl, 4-pyridyl, benzoyl, and trichloromethyl spin adducts of α-phenyl tert-butyl nitrone (PBN) as well as for the tert-butoxyl adduct of 5,5-dimethylpyrroline-N-oxide (DMPO) have been obtained as a function of solvent (30 solvents). A useful linear relationship between the β-H hfsc and the N-hfsc of each aminoxyl is found except for the benzoyl adduct of PBN. Some speculations regarding the structural significance of these correlations is presented.

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