Separation of hot-carrier-induced interface trap creation and oxide charge trapping in PMOSFETs studied by hydrogen/deuterium isotope effect

2001 ◽  
Vol 22 (4) ◽  
pp. 188-190 ◽  
Author(s):  
K. Cheng ◽  
J. Lee ◽  
J.W. Lyding ◽  
Young-Kwang Kim ◽  
Young-Wug Kim ◽  
...  
1972 ◽  
Vol 50 (5) ◽  
pp. 678-689 ◽  
Author(s):  
D. H. Hunter ◽  
S. K. Sim

The mechanism of the cyclization and 1,3-proton shift of 1,3,5-triaryl-2,4-diaza-1,3-pentadienes (1) catalyzed by phenyllithium and by potassium methoxide–methanol has been studied. On the basis of substituent effects, hydrogen–deuterium exchange, isotope effects, and solvent effects, it was deduced that both the cyclization and prototropy involve a common W-shaped carbanion which rapidly cyclizes. A kinetic deuterium isotope effect of 2 was calculated for protonation of this intermediate carbanion in methanol.


2001 ◽  
Vol 48 (4) ◽  
pp. 813-815
Author(s):  
Zhi Chen ◽  
Kangguo Cheng ◽  
Jinju Lee ◽  
J.W. Lyding ◽  
K. Hess ◽  
...  

1972 ◽  
Vol 50 (5) ◽  
pp. 618-626 ◽  
Author(s):  
N. H. Werstiuk ◽  
R. R. MacDonald ◽  
R. W. Ouwehand ◽  
W. L. Chan ◽  
F. P. Cappelli ◽  
...  

The deuterionorborneols 2a, b, c, and e have been prepared and converted to the brosylates 1a, b, c, and e. The deuterium isotope effects determined spectrophotometrically for solvolysis in HOAc–KOAc are 1.00 ± 0.01, 1.01 ± 0.01, 0.99 ± 0.01, and 1.11 ± 0.01, respectively. These data establish that: (a) a steric deuterium isotope effect does not operate at C-5 and therefore probably not at C-6; (b) hyperconjugative stabilization of the norbornonium ion to the C-5 hydrogens is confirmed to be not important, and (c) provides the first experimental evidence that the hydrogen (deuterium) shift – internal return pathway contribution to the γ-deuterium isotope effects observed for 1d and e is minor.


1974 ◽  
Vol 60 (1) ◽  
pp. 127-132 ◽  
Author(s):  
Ysbrand Haven ◽  
Rodney C. Williams ◽  
Phillip J. Hamrick ◽  
Howard Shields

1976 ◽  
Vol 54 (14) ◽  
pp. 2339-2341 ◽  
Author(s):  
George Stanley Dyson ◽  
Peter James Smith

The mechanism of the reaction of 9-(4-substituted benzyl)fluorene-9-trimethylammonium ions with ethoxide is a normal E2 process. The magnitude of the primary hydrogen–deuterium isotope effect at 60 °C increased with increasing electron-donating ability of the 4-substituent, i.e., 4.15, 5.10, 5.34, 5.65, 5.75, and 5.91 for the 4-CF3, 4-Br, 4-Cl, 4-H, 4-CH3, and 4-OCH3 substituents, respectively. The magnitude of the nitrogen isotope effect at 70 °C decreased with increased electron-donating power of the 4-substituent, i.e., [(k14/k15)–1]100 = 1.24, 0.95, 0.92, 0.91, and 0.80 for the 4-CF3, 4-F, 4-H, 4-CH3, and 4-OCH3 substituents, respectively. A small Hammett ρ value of +1.33 was observed for the reaction. It is concluded that the reaction proceeds via a transition state where the proton is more than one-half transferred to base. It is further concluded that for a reaction in which the 4-substituents decrease the rate, both carbon–hydrogen and carbon–nitrogen bond rupture is more advanced in the transition state. This variance with Hammond's postulate is discussed in the light of steric crowding at the transition state.


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