Burks

The three sets of data chosen for the comparisons between experiment and simulation have been supplied by Dr. S. K. Burke of the DSTO Aeronautical and Maritime Research Laboratory (Melbourne, Australia). 

Walton D J, Phull S S, Chyla A, Lorimer J P, Mason T J, Burke L D, Murphy M, Compton R G, Ekiund J C and Page S D 1995 Sonovoltammetry at platinum electrodes surface phenomena and mass transport processes J. Appl. Electrochem. 25 1083... 

Burke P G 1996 Atomic, Molecular and Optical Physics Handbook ed G W Drake (New York American Institute of Physics Press) oh 45... 

Hammer B, Hansen L B and Norskov J K 1999 Improved adsorption energetics within density functional theory using revised Perdew-Burke-Enerhof functionals Phys. Rev. B 59 7413-21... 

Perdew J P, Burke K and Ernzerhof M 1996 Generaiized gradient approximation made simpie Phys. Rev. Lett. 77 3865... 

Coble R L and Burke J E 1963 Sintering in oeramios Progress in Ceramic Science vol 3, ed J E Burke (New York MaoMillan) pp 197-251... 

Burke J E and Rosoiowski J H 1976 Sintering Reactivity of Solids (Treatise on Solid State Chemistry vol ed N B Hannay (New York Pienum) pp 621-59... 

The equilibrium constants obtained using the metal-ion induced shift in the UV-vis absorption spectrum are in excellent agreement with the results of the Lineweaver-Burke analysis of the rate constants at different catalyst concentrations. For the copper(II)ion catalysed reaction of 2.4a with 2.5 the latter method gives a value for of 432 versus 425 using the spectroscopic method. 

In a Lineweaver-Burke analysis Mk pp is plotted as a function of l/[catalyst]. The intercept of this plot on the y-axis provides the value of Vk-yA, whereas the intercept on the x-axis yields the value for 1/K,z. 

Some examples of the use of a temporary additional site of coordination have been published. Burk and Feaster have transformed a series of ketones into hydrazones capable of chelating to a rhodium catalyst (Scheme 4.7). Upon coordination, enanti os elective hydrogenation of the hydrazone is feasible, yielding N-aroylhydrazines in up to 97% ee. Finally, the hydrazines were transformed into amines by treatment with Sml2. 

Inspired by the work of Burk and Feaster ) we attempted to use (2-pyridyl)hydrazine (4.36) as a coordinating auxiliary (Scheme 4.10). Hydrazines generally react effidently with ketones and aldehydes. Hence, if satisfactory activation of the dienophile can be achieved through coordination of a Lewis acid to the (2-pyridyl)hydrazone moiety in water. Lewis-add catalysis of a large class of ketone- and aldehyde-activated dienophiles is antidpated Subsequent conversion of the hydrazone group into an amine functionality has been reported previously by Burk and Feaster ... 

The majority of preparative methods which have been used for obtaining cyclopropane derivatives involve carbene addition to an olefmic bond, if acetylenes are used in the reaction, cyclopropenes are obtained. Heteroatom-substituted or vinyl cydopropanes come from alkenyl bromides or enol acetates (A. de Meijere, 1979 E. J. Corey, 1975 B E. Wenkert, 1970 A). The carbenes needed for cyclopropane syntheses can be obtained in situ by a-elimination of hydrogen halides with strong bases (R. Kdstcr, 1971 E.J. Corey, 1975 B), by copper catalyzed decomposition of diazo compounds (E. Wenkert, 1970 A S.D. Burke, 1979 N.J. Turro, 1966), or by reductive elimination of iodine from gem-diiodides (J. Nishimura, 1969 D. Wen-disch, 1971 J.M. Denis, 1972 H.E. Simmons, 1973 C. Girard, 1974),... 

As final examples, the intramolecular cyclopropane formation from cycloolefins with diazo groups (S.D. Burke, 1979), intramolecular cyclobutane formation by photochemical cycloaddition (p. 78, 297f., section 4.9), and intramolecular Diels-Alder reactions (p. 153f, 335ff.) are mentioned. The application of these three cycloaddition reactions has led to an enormous variety of exotic polycycles (E.J. Corey, 1967A). 

A plot of 1/v versus 1/[S], which is called a double reciprocal, or Lineweaver-Burk plot, is a straight line with a slope of Km/Vmax) a y-intercept of 1/Vmax> and an x-intercept of-l/Km (Figure 13.11). 

The three reversible mechanisms for enzyme inhibition are distinguished by observing how changing the inhibitor s concentration affects the relationship between the rate of reaction and the concentration of substrate. As shown in figure 13.13, when kinetic data are displayed as a Lineweaver-Burk plot, it is possible to determine which mechanism is in effect. 

Effect of the concentration of inhibitor on the Lineweaver-Burk plots for (a) competitive inhibition, (b) noncompetitive inhibition, and (c) uncompetitive inhibition. The inhibitor s concentration increases in the direction shown by the arrows. 

Lineweaver-Burk plot a graphical means for evaluating enzyme kinetics, (p. 638)... 

S. Procha2ka in J. Burke, A. Gomm, and R. Kat2, eds.. Ceramicsfor High Peformance Applications, Brook HiU, Chestnut FTill, Mass., 1974, p. 239. 

Y. Tran and L. J. Burke, Acronyms and Terminologyfor Havy Explosives, MP87-304, NSWC, White Oaks, Md., Jan. 1988. 

---