Atkinson studies

Two triazaphenanthrenes have been studied recently by Atkinson and Mattocks. 10-Phenyl- (150 R = H) and lO-phenyl-4-amino-1,3,9-triazaphenanthrene (150 R = NH2) were both shown to quater-nize at N-3. The methiodide (151 R = NH2) of the amino compound... 

Asymmetric aziridination of a,P-unsaturated esters by use of N-nitrenes was studied in great detail by Atkinson and co-workers [34, 35]. Here, lead tetraacetate-mediated oxidative addition of N-aminoquinazolone 30 (Scheme 3.10) to a-methy-lene-y-butyrolactone 32 was reported to proceed with complete asymmetric indue-... 

Explicit mechanisms attempt to include all nonmethane hydrocarbons believed present in the system with an explicit representation of their known chemical reactions. Atmospheric simulation experiments with controlled NMHC concentrations can be used to develop explicit mechanisms. Examples of these are Leone and Seinfeld (164), Hough (165) and Atkinson et al (169). Rate constants for homogeneous (gas-phase) reactions and photolytic processes are fairly well established for many NMHC. Most of the lower alkanes and alkenes have been extensively studied, and the reactions of the higher family members, although little studied, should be comparable to the lower members of the family. Terpenes and aromatic hydrocarbons, on the other hand, are still inadequately understood, in spite of considerable experimental effort. Parameterization of NMHC chemistry results when NMHC s known to be present in the atmosphere are not explicitly incorporated into the mechanism, but rather are assigned to augment the concentration of NMHC s of similar chemical nature which the... 

Sherman DG, Atkinson RR Chippendale T, Levin KA, Ng K, Futrell N, Hsu CY, Levy DE. Intravenous ancrod fortreatment of acute ischemic stroke The STAT study A randomized controlled trial. Stroke Treatment with Ancrod Trial. JAMA. 2000 283 2395-2403. 

Lyden P, Shuaib A, Ng K, Levin K, Atkinson RP, Rajput A, Wechsler L, Ashwood T, Claesson L, Odergren T, Salazar-Gmeso E. Clomethiazole acute stroke study in ischemic stroke (class-i) final results. Stroke 2002 33 122-128. 

A. M. Harris, G. W. Atkinson, R. Graham, R. A. "Atmospheric Chemistry of Hydrazines Gas Phase Kinetics and Mechanistic Studies," Final Report, U.S. Air Force Contract No. F08635-78-C-0307, July 31, 1980. 

Carter WPL, R Atkinson (1987) An experimental study of incremental hydrocarbon reactivity. Environ Sci Technol 21 670-679. 

KE Price, Z Zolli, Jr, JC Atkinson, HG Luther. Antibiotic inhibitors. II. Studies on the inhibitory action... 

Almond, M., S. Eversfield, and S. Atkinson (2005), A window on the past Scientific study and chemical analysis in archaeological research, Chemistry Industry 14, 14-17. 

Winer, A.M., Damall, K.R., Atkinson, R. Pitts, Jr., J.N. (1979) Smog chamber study of the correlation of hydroxyl radical rate constants with ozone formation. Environ. Sci. Technol. 7, 622-626. 

Microbes tend to form flocks as they grow, into which nutrients and dissolved oxygen must diffuse. The rate of growth thus depends on the diffusional effectiveness. This topic is developed by Atkinson (1974). Similarly enzymes immobilized in gel beads, for instance, have a reduced catalytic effectiveness analogous to that of porous granular catalysts that are studied in Chapter 7. For the M-M equation this topic is touched on in problems P8.04.15 and P8.04.16. 

The effect of using a new rate coefficient for the reaction HO2+NO of 8.4lx 10-12cm-3 molecule-1 s-1 at 298 K (C. Percival, personal communication) instead of the 8.91xl0-12cm-3 molecule-1 s-1 at 298K used in the MCMv3.0 (Atkinson et al., 2001) was negligible for both HO2 and OH for the clean conditions studied for example, the variation in [HO2] is about 0.02% at midday on 7 February. 

Colledge NR, Wilson 1A, Macintyre CC et al. (1994) The prevalence and characteristics of dizziness in an elderly community. Age Ageing 23(2) 117-120 The Consensus Committee of the American Autonomic Society and the American Academy of Neurology. (1996) Consensus statement on the definition of orthostatic hypotension, pure autonomic failure, and multiple system atrophy. Neurology 46(5) 1470 Cooper C, Atkinson El, lacobsen SI et al. (1993) Population-based study of survival after osteoporotic fractures. Am 1 Epidemiol 137(9) 1001-1005 Cummings SR and Melton LI (2002) Epidemiology and outcomes of osteoporotic fractures. Lancet 359(9319) 1761-1767... 

C. Atkinson, H.E. Skor, E.D. Fitzgibbons, D. Scholes, C. Chen, K. Wahala, S.M. Schwartz and J.W. Lampe, Urinary equol excretion in relation to 2-hydroxyestrone and 16 alpha-hydroxye-strone concentrations an observational study of young to middle-aged women.. /. Steroid Biochem. Mol. Biol. 86 (2003) 71-77. 

Atkinson, R., B. J. Finlayson, and J. N. Pitts, Jr. Photoionization mass spectrometer studies of gas phase ozone-olefin reactions. J. Amer. Chem. Soc. 95 7592-7599, 1973. 

Photolytic. Fukuda et al. (1988) studied the photodegradation of acenaphthene and alkylated naphthalenes in distilled water and artificial seawater using a high-pressure mercury lamp. Based upon a rate constant of 0.23/h, the photolytic half-life of acenaphthene in water is 3 h. Behymer and Hites (1985) determined the effect of different substrates on the rate of photooxidation of acenaphthene using a rotary photoreactor equipped with a 450-W medium pressure mercury lamp (X = 300-410 nm). The photolytic half-lives of acenaphthene absorbed onto silica gel, alumina, and fly ash were 2.0, 2.2, and 44 h, respectively. The estimated photooxidation half-life of acenaphthene in the atmosphere via OH radicals is 0.879 to 8.79 h (Atkinson, 1987). 

Photolytic. Atkinson (1985) reported a rate constant of 2.59 x 10 " cmVmolecule-sec at 298 K. Based on an atmospheric OH concentration of 1.0 x 10 molecule/cm , the reported half-life of allyl alcohol is 0.35 d. The reaction of allyl alcohol results in the OH addition to the C=C bond (Grosjean, 1997). In a similar study, Orlando et al. (2001) studied the reaction of allyl alcohol with OH radicals at 298 K. Photolysis was conducted using a xenon-arc lamp within the range of 240-400 nm in synthetic air at 700 mmHg. A rate constant of 4.5 x 10 " cm /molecule-sec was reported. Products identified were formaldehyde, glycolaldehyde, and acrolein. 

Chemical/Physical. Atkinson et al. (2000) studied the kinetic and products of the gas-phase reaction of 2-heptanone with OH radicals in purified air at 25 °C and 740 mmHg. A relative rate constant of 1.17 x 10 " cmVmolecule Sec was calculated for this reaction. Reaction products identified by GO, FTIR, and atmospheric pressure ionization tandem mass spectroscopy were (with respective molar yields) formaldehyde, 0.38 acetaldehyde, L0.05 propanal, X0.05 butanal, 0.07 pentanal, 0.09 and molecular weight 175 organic nitrates. 

Chemical/Physical. The gas-phase reaction of ozone with pyridine in synthetic air at 23 °C yielded a nitrated salt having the formula [CeHsNHJ NOs (Atkinson et al., 1987). Ozonation of pyridine in aqueous solutions at 25 °C was studied with and without the addition of ferf-butyl alcohol (20 mM) as a radical scavenger. With tert-hniyX alcohol, ozonation of pyridine yielded mainly pyridine W-oxide (80% yield), which was very stable towards ozone. Without terf-butyl alcohol, the heterocyclic ring is rapidly cleaved forming ammonia, nitrate, and the amidic compound W-formyl oxamic acid (Andreozzi et al., 1991). 

Chemical/Physical. Under atmospheric conditions, the gas-phase reaction of o-xylene with OH radicals and nitrogen oxides resulted in the formation of o-tolualdehyde, o-methylbenzyl nitrate, nitro-o-xylenes, 2,3-and 3,4-dimethylphenol (Atkinson, 1990). Kanno et al. (1982) studied the aqueous reaction of o-xylene and other aromatic hydrocarbons (benzene, toluene, w and p-xylene, and naphthalene) with hypochlorous acid in the presence of ammonium ion. They reported that the aromatic ring was not chlorinated as expected but was cleaved by chloramine forming cyanogen chloride. The amount of cyanogen chloride formed increased at lower pHs (Kanno et al., 1982). In the gas phase, o-xylene reacted with nitrate radicals in purified air forming the following products 5-nitro-2-methyltoluene and 6-nitro-2-methyltoluene, o-methylbenzaldehyde, and an aryl nitrate (Chiodini et ah, 1993). 

Aramaki and Atkinson were also active in work on the spiro-oxazines [65]. They noted that for NOSH in many polar and nonpolar solvents the picosecond time-resolved resonance Raman spectra simply built up over 50 psec with no shape evolution. The same finding was concluded from transient absorption measurements over the same time scale. The spectra/absorbances were then constant for 1.5 nsec. These authors suggest that only two isomers can be expected to contribute to the merocyanine spectra because those trans about the y-methene bridge bond attached to the naphthalene ring are sterically crowded due to short interproton distances. There was no evidence for the X transient in their study however, the 50-psec convoluted pulse profile may be expected to mask this sortlifetime species even if it were present. 

Atkinson R, Carter WPL, Darnall KR, et al. 1980. A smog chamber and modeling study of the gas phase NO air photo-oxidation of toluene and the cresols. Int J Chem Kinet 12 779-836. 

Atkinson, R.J. (1976) The formation of iron(III) oxide hydroxides from iron(III) oxalate. Aust. J. Chem. 29 2149-2158 Atkinson, R.J. Parfitt, R.L. Smart, R.S.C. (1974) Infrared study of phosphate adsorption on goethite. J. Chem. Soc. Earaday Trans. I. 70 1472-1479... 

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