Parameters used to model the An3+ (An = Ac and Cm) L3-edge EXAFS spectra from Ac3+ and Cm3+ dissolved in (NH4)O2CMe(aq):HO2CMe(aq) buffered (pH 5.5) aqueous solutions. Note, the amplitude reduction factors (S02) were fixed at 0.9.
| Analyte (concentration) | Path | R (Å) | CN | σ 2×103 |
|---|---|---|---|---|
| Ac (0.2 M)a | Ac–OH2O | 2.64(1) | 9(1) | 12(3) |
| Ac (15 M)a | Ac–OH2O | 2.56(6) | 6(1) | 9(3)b |
| Ac–OO2CMe | 2.69(6) | 5(2) | 9(3)b | |
| Ac–CO2CMe | 3.19(3) | 3(1)c | 4(2)d | |
| Ac–CO2CMe | 3.72(3) | 3(1)c | 4(2)d | |
| Ac–O–C–Ac | 3.41(3) | 6(1) | 4(2)d | |
| Cm (0.1 M)e | Cm–OH2O | 2.47(1) | 8(1) | 10(2) |
| Cm (4 M)e | Cm–OO2CMe+H2O | 2.47(2) | 9(1) | 12(2) |
| Cm–CO2CMe | 2.91(1) | 2(1) | 3(1) | |
| Cm (15 M)e | Cm–OO2CMe+H2O | 2.46(1) | 9.1(8) | 12(5) |
| Cm–CO2CMe | 3.27(4)f | 4.5(5)g | 7(4)h | |
| Cm–CO2CMe | 3.56(4)f | 4.5(5)g | 7(4)h | |
| Cm–O–C–Cm | 3.71(3) | 9.1(8) | 7(4)h |
a
Ac samples: So2 (fixed) = 0.9, ΔEo = 9.0(3) eV 1.15 ≤ R ≤ 4 Å, 2.3 ≤ k ≤ 11.0, Nind = 15.8.
b
Constrained equivalently.
c
Constrained equivalently.
d
Constrained equivalently.
e
Cm samples: So2 (fixed) = 0.9, ΔEo = −0.3(5) eV 1.0 ≤ R ≤ 3.5 Å, 1.4 ≤ k ≤ 12.0, Nind = 16.9.
f
Constrained to the same shift (Δ) in R (Å).
g
Constrained equivalently.
h
Constrained equivalently.