Yates studies

It is unlikely that a free carbocation (or a solvent-separated ion pair) is the intermediate in these addition reactions, however. Rolston and Yates studied the addition of bromine to derivatives of styrene in acetic acid and other solvents. In acetic acid, the products were found to be the 1,2-dibromo addition products plus variable amoimts of the bromoacetoxy products derived from solvent. For all of the styrene derivatives studied except ) ,) -dimethylstyrene, the solvent incorporation product in each case was exclusively the l-acetoxy-2-bromo compound—the product expected from nucleophilic attack of solvent on a benzylic carbocation. The dibromo and bromoacetoxy products were formed with different stereoselectivity. The reaction of ds-jS-methylstyrene (16) produced ( )-t/ireo-l,2-dibromo-l-phen-ylpropane (15, 58%), ( )-eryf/iro-l,2-dibromo-l-phenylpropane (14, 22%), and ( )-t/ireo-l-acetoxy-2-bromo-l-phenylpropane (17, 20%). 

M. Suzuki, ed.. Fundamentals of Adsorption, Studies in Surface Science and Catalysis, B. Delman and J. T. Yates, eds., Elsevier, New York, 1993. 

Yates J T and Garland C 1961 Infrared studies of carbon monoxide chemisorbed on nickel surfaces J. Catal. 65 617-24... 

KJ. Uram, L. Ng, and J.R.Yates Jr., Electrostatic effects between adsorbed species-The K-CO interaction on Ni(lll) as studied by infrared reflection - absorption spectroscopy, Surf. Sci. 177, 253-277 (1986). 

Recent studies by Pincock and Yates (32, 33) have demonstrated the intermediacy of vinyl cations in the electrophilic bromination of arylmethyl-acetylenes in acetic acid. The rates of addition of Brj to a number of substituted phenylmethylacetylenes in acetic acid follow the general equation... 

Catalytic Properties. In Delmon B, Yates JT (eds) Studies in Surface Science and... 

The smallest molecule in the class is methanethiol, which has been studied at several surfaces as an indicator for the behaviour of larger thiols. On all metals, except gold, adsorption results in the dissociation of the S H bond. Yates and co-workers suggested47 that the S-H bond of methanethiol is also stable on silver, dissociation being catalysed by adsorbed sulfur present at defect sites. However, this contradicts Jaffey and Madix s results,56 which showed S-H bond cleavage below 350 K in their study of ethanethiol on Ag(lll). 

Frankcombe, K. E., Cavell, K. J., Knott, R. B., Yates, B. F., 1997, Competing Reaction Mechanisms for the Carbonylation of Neutral Palladium(II) Complexes Containing Bidentate Ligands a Theoretical Study ,... 

Yates, Frances Amelia. The French Academies of the sixteenth century. Studies of the Warburg Institute, no. 15. London Warburg Institute, University of London, 1947. 

A study of Dijksterhuis s "The mechanization of the world picture" (1959), Koyre s "From the closed world to the infinite universe" (1957), and Yates s "Giordano Bruno and the hermetic traditon" (1964)... 

Perhaps the first examples of this type of reaction resulting from type I cleavage were reported by Yates in a study of the photochemistry of cyclocamphanone and nortricyclanone,... 

Garland et al. (29) studied the spectra of CO chemisorbed on nickel films and explained the differences observed between them after changes of the evaporation conditions along the same lines as did Yates and Garland (27) for supported catalysts. We hold that there is no conclusive evidence in favor of the existence of bridge-bonded CO in nickel and share Bly-holder s opinion (32) that the infrared spectra can be explained on the assumption that CO is bonded in linear form only. 

Bromination can be a second-, third- or higher-order reaction, first-order in olefin but first-, second- or higher-order in bromine. Most of the early kinetic studies were focused on this complex situation (De la Mare, 1976). It is now known that bromine concentrations less than 10 3 m are necessary to obtain simple or workable kinetic equations. This limit varies slightly with the solvent for instance, in methanol 10 2 m bromine leads to convenient rate equations (Rothbaum et al, 1948) but in acetic acid 10 3 m is the highest that can be used (Yates et al, 1973). 

Basu, P., Ballinger, T.H. and Yates Jr., J.T. (1988). Wide temperature range IR spectroscopy cell for studies of adsorption and desorption on high area solids. Rev. Sci. Instrum. 59, 1321-1327... 

Yates, B.F. Radom, L. Intramolecular Hydrogen Migration in Ionized Amines a Theoretical Study of the Gas-Phase Analogues of the Hofmann-Loffler and Related Rearrangements. J. Am. Chem. Soc. 1987,109,2910-2915. 

Aspartate transcarbamoylase (ATCase) from Escherichia coli is the most studied and best known regulatory enzyme. Yates and Pardee (1956) were the first to propose that the activity of ATCase is controlled by end product inhibition. This feedback inhibition was later studied in more detail by Gerhart and Pardee (1961, 1962, 1963). The three-dimensional structure of ATCase was determined by Lip-scombe and his coworkers [Wiley etal. (1971), Wiley and Lipscomb (1968), Warren etal. (1973)]. 

Postmortem (Benwell et al. 1988 Breese et al. 1997) and laboratory (Yates et al. 1995) studies demonstrate that smokers have widespread upregulation of nAChRs, likely related to desensitization of these receptors from nicotine exposure. Many animal studies also demonstrate upregulation of nAChRs in response to chronic nicotine administration (e.g., Pauly et al. 1996 Shoaib et al. 1997 Zhang et al. 2002). Thus, nAChRs are a natural target for tracer development in the pursuit of a greater understanding of tobacco dependence and other illnesses with abnormal nAChR levels. 

Further evidence for nitrogen as the site of protonation of amides in largely aqueous acid comes from studies of substituent effects on the p/Sfa Value of benzamide (Edward et al., 1960 Yates and Stevens, 1965). It has been observed that the pi g-values are correlated with a-constants of the substituents, rather than with o. This means that the structure of the dominant form of the cation is N-protonated as in [112], because resonance interactions of para-substituents in this kind of cation are similar to those in benzoic acid. The p-value (0 92)... 

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