Y Effect

If an H atom in an alkane R-// is replaced by a substituent X, the C chemical shift 8c in the a-position increases proportionally to the electronegativity of X (-/ effect). In the (1-position, Sc generally also increases, whereas it decreases at the C atom y to the substituent (y-effect, see Section 2.3.4). More remote carbon atoms remain almost uninfluenced (dSc 0). 

Table 2.12. chemical shifts (relative configurations of cycloalkanes, pyranoses and alkenes (application of y-effects) The shifts which are printed in boldface reflect y-effects on C atoms in the corresponding... 

The chemical shift of a nucleus depends in part on its spatial position in relation to a bond or a bonding system. The knowledge of such anisotropic effects is useful in structure elucidation. An example of the anisotropic effect would be the fact that axial nuclei in cyclohexane almost always show smaller H shifts than equatorial nuclei on the same C atom (illustrated in the solutions to problems 37, 47, 48, 50 and 51). The y-effect also contributes to the corresponding behaviour of C nuclei (see Section 2.3.4). 

Jch coupling constants 13c chemical shifts (y effects)... 

TEL was not the only way to increase octane number. Those few companies who did not wish to do business with Jersey Standard, sought other means to produce a viable premium gasoline. TEL represented the most serious threat to the traditional gasoline product. It was cheap, vei y effective, and only 0.1 percent of TEL was required to increase the octane number 10 to 15 points. In contrast, between 50 to 100 times this concentration was required of alternative octane enhancers to achieve the same effect. 

Kato, M., Inoue, T., Goto, K., Ito, G. and Shimizu, Y., Effect of Dissolved Oxidising Agents and Inhibitors on Pitting Corrosion of Aluminium in Water , Aluminium, 49, 289 (1973) Richardson, J. A. and Godwin, A. W., Localised Corrosion of Stainless Steel During Food Processing , Br. Corros. J., 8, 259 (1973)... 

If there is a large pinhole leak a few inches below the liquid surface, it will behave like a leak above the liquid. However, a small pinhole leak in the same location may have zero inleakage due to capillar y effects. The problem becomes complicated as the depth becomes large, and... 

Scrima L, Hartman PG, Johnson EH, et al The effects of gamma-hydroxybutyrate on the sleep of narcolepsy patients a double blind study. Sleep 13 479 90, 1990 Series F, Series 1, Cormier Y Effects of enhancing slow-wave sleep by gamma-hydroxybutyrate on obstructive sleep apnea. Am Rev Respir Dis 143 1378-1383, 1992 Shannon M Methylenedioxymethamphetamine (MDMA, ecstasy ). Pediatr Emerg Care 16 377-380, 2000... 

Yuasa, T., Kadota, S., Tsue, M., Kono, M., Nomuta, H., and Ujiie, Y, Effects of energy deposition schedule on minimum ignition energy in spark ignition of methane-air mixtures, Proc. Combust. Inst., 29, 743, 2002. 

Crowell RM, Olsson Y. Effect of extracranial-intracranial vascular bypass graft on experimental acute stroke in dogs. J Neurosurg 1973 38 26-31. 

Fig. 4.29. y- effect in butane at room temperature (20 C) under different pressures PiMt - 572 Torr (f), 250 Torr (2). Curve 3 displays the results of calculation based on equation (4.26) under the given experimental conditions (see curves i and 2). 

Ito, K., Kusuhara, H., Sugiyama, Y., Effects of intestinal CYP3A4 and P-glycoprotein on oral drug absorption -theoretical approach, Pharm. Res. 

Yoshio, M., Wang, H., Fukuka, K., Hara, Y., and Adachi, Y., Effect of carbon coating on electrochemical performance of treated natural graphite as lithium-ion battery anode material, J. of Electrochem. Soc. (2000) 147 (4) 1245-1250. 

Kato T., Kubota M., Kobayashi N., Suzuoki Y., Effective utilization of by-product oxygen from electrolysis hydrogen production, Energy, 30, 2580-2595, 2005. 

Ogura, S., Kohno, M., Sato, K., and Inoue, Y., Effects of RuOz on activity for water decomposition of a Ru02/Na2Ti307 photocatalyst with zigzag layer structure,. Mater. Chem., 8,2335,1998. 

Additional molecular mechanisms must also mediate IFN-y effects, as it promotes a marked clinical improvement in some CGD patients without enhancing phagocyte activity. IFN-y s demonstrated ability to stimulate aspects of cellular and humoral immunity (e.g. via T- and B-lymphocytes), as well as NK cell activity, is most likely responsible for these observed improvements. 

Lefkowitz, S.S. and Chiang, C.Y., Effects of certain abused drugs on hemolysin forming cells, Life ScL, 17, 1763, 1975. 

Coupling of the more activated enamine 335, obtained in two steps from tabersonine, with 21-cyano-20-epipandoline (331) in the presence of AgBF4 in THF solution gave the dimer 334 in 20% yield. Its structure was based on spectral data, particularly CMR. Diagnostic were the chemical shifts for C-2 at 104.1 ppm (versus 103.4 ppm in ervafoline) and the upfield shift of C-6 at 35.3 ppm (ascribed to the -y effect). 

Koch and coworkers49 found that the C-l shifts of isopropyl and tert-butyl a-D-glucopyranoside respectively lie 4 and 7.7 p.p.m. to higher field than that of the methyl glycoside this was assumed to be wholly due to the y-effect between methyl groups of the aglycons and the an-omeric centers. Isopropyl a-D-glucopyranoside can exist as three retainers 3, 4, and 5, and it may be seen that the last two contribute to... 

Carbon-13. Steric compression by axial P substituents produces a so-called y-effect by their interaction with the two axial protons on the same side of the ring, and there is a resultant upfield shift of the carbon atoms bearing the axial protons. This effect has been noted for a number of dioxaphosphorinans (22)42>43 as well as for phos-phorinans.22 A small but significant shift of the C-4 resonance occurs when the... 

Lim, G., and Wang, C. Y. Effect of hydrophobic polymer content in GDL on power performance of a PEM fuel cell. Electrochimica Acta 2004 49 4149-4156. 

Shitara Y, Kato Y, Sugiyama Y. Effect of brefeldin A and lysosomotropic reagents on intracellular trafficking of epidermal growth factor and transferrin in Madin-Darby canine kidney epithelial cells. J Control Release 1998 55(1) 35 3. 

Inaba, K., Shiraishi, H.. and Soma. Y. Effects of salinity. pH. and temperatnre on aqneons solnbility of font organotin compounds. Water Res., 29(5) 1415-1417, 1995. 

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