Table 3.
EXAFS Data Refinements for 2, 2-MeOH, and 2-MeCN
2 (in CH2Cl2) | 2-MeOH | 2-MeCN | |
---|---|---|---|
NN+O | 3 Na | 3 N + 1 Ob | 4 N |
rN+O (Å) | 2.000 ± 0.018c | 2.033 ± 0.016 | 2.017 ± 0.016 |
σN+O (Å)d | 0.075 ± 0.030 | 0.093 ± 0.025 | 0.108 ± 0.019 |
NS | 2 S | 2 S | 2 S |
rS (Å) | 2.117 ± 0.015 | 2.179 ± 0.021 | 2.179 ± 0.010 |
σS (Å) | 0.070 ± 0.019 | 0.093 ± 0.025 | 0.067 ± 0.012 |
BVS | 4.09 ± 0.13e | 4.07 ± 0.14 | 4.28 ± 0.09 |
ε2 | 2.2 | 2.0 | 0.7 |
The number of N and S scatterers was held fixed at the values shown.
For 2-MeOH, an oxygen scatterer was included with its r and σ constrained to be the same as for the nitrogen shell.
Uncertainty range is for ε2 no more than 1.0 greater than the minimum value reported.
σ2, the Debye–Waller disorder parameter, was refined. The best-fit values and uncertainty ranges were converted to σ values because the uncertainty ranges were more symmetrical when expressed in σ rather than σ2.
Uncertainty range determined by mapping ε2 in a series of refinments in which BVS was fixed to a value (4.00, for instance) and rN+O and the two σ parameters were refined, while rS was constrained to be consistent with the fixed BVS.