Table 1.
Observed first-order rate constants and normalized amplitude parameters for fits of the biexponential function to the decay kinetics of the 2H-substrate radical state, and 1H/2H hydrogen isotope effects (IE) at different temperatures. The standard deviations for the kobs and Aobs parameters represent at least three separate determinations at each temperature. The 1H-substrate radical kobs values used to calculate IEf and IEs were determined previously.11
| T (K) | kobs,f (s−1) | Aobs,fa | kobs,s (s−1) | Aobs,sb | R2c | IEf | IEs |
|---|---|---|---|---|---|---|---|
| 207 | 1.1±0.3 ×10−3 | 0.53±0.05 | 2.9±0. 6 ×10−4 | 0.47±0.05 | 0.9997 | 1.4±0. 2 | 1.00±0.22 |
| 203 | 5.7±0.8 ×10−4 | 0.52±0.06 | 1.1±0. 1 ×10−4 | 0.48±0.06 | 0.9999 | 1.5±0. 1 | 0.73±0.05 |
| 200 | 4.4±1.2 ×10−4 | 0.41±0.09 | 7.7±1.8 ×10−5 | 0.59±0.09 | 0.9997 | 1.3±0. 1 | 0.61±0.04 |
| 197 | 2.6±0.2 ×10−4 | 0.44 ±0.11 | 3.6±0.8 ×10−5 | 0.56±0.11 | 0.9998 | 1.4±0.1 | 0.67±0.07 |
| 193 | 1.2±0.2 ×10−4 | 0.37±0.02 | 1.5±0. 3 ×10−5 | 0.63±0.02 | 0.9995 | 1.2±0.3 | 0.87±0.08 |
| 190 | 5.3±0.5 ×10−5 | 0.38±0.02 | 6.1±0. 1 ×10−6 | 0.62±0.02 | 0.9995 | 1.4±0.1 | 0.85±0.03 |
a
The relative fitted amplitude for the fast phase, normalized to the sum, Aobs,f+Aobs,s.
b
The relative fitted amplitude for the slow phase, normalized to the sum, Aobs,f+Aobs,s.
c
R is Pearson’s correlation coefficient.