Table 2. The energy shift (ΔE0), bond distance (R), coordination number (CN), and Debye–Waller factor (σ2) fitting parameters used to model the room-temperature AnIII L3-edge solution-phase EXAFS spectra from AnIII cations (AnIII = CmIII, AmIII, AcIII) dissolved in HNO3 (0.05, 4, and 16 M). Data were additionally compared with the previously measured AnIII aquo complexes.12,21,46,47 In each of our models, the structural amplitude reduction factors (S02) were set to 0.9 a .
| ΔE0 (eV) | R M–O (Å) | CNbound oxygen | σ bound oxygen 2 | R M···N (Å) | CNnitrogen | R M···O terminal oxygen | σ terminal oxygen 2 | |
| Cm aquo (0.25 M HCl),46,* | –13.0 | 2.450 ± 0.002 | 10.2 ± 0.3 | 0.009 (fixed) | — | — | — | — |
| Cm aquo (1 M HClO4),47,* fit 1 | –2.0 ± 0.9 | 2.469 ± 0.007 | 7.0 ± 0.4 | 0.0071(8) | — | — | — | — |
| Cm aquo (1 M HClO4),47,* fit 2 | –0.7 ± 0.7 | 2.470 ± 0.006 | 6 (fixed) | 0.0053(2) | — | — | — | — |
| 2.63 ± 0.02 | 3 (fixed) | 0.009 (2) | ||||||
| Cm (HNO3, 0.05 M) | –5.5 ± 0.8 | 2.47 ± 0.01 | 9.6 ± 0.7 | 0.009(1) | — | — | — | — |
| Cm (HNO3, 4 M) | 1.5 ± 1.3 | 2.45 ± 0.01 | 7 (fixed) | 0.007(3) | 2.93 ± 0.07 | 1 fixed | 4.25 ± 0.03 | 0.006 (4) |
| 2.54 ± 0.05 | 2 (fixed) | |||||||
| 2.63 ± 0.04 | 2 (fixed) | |||||||
| Cm (HNO3, 16 M) | 3.4 ± 1.1 | 2.49 ± 0.02 | 8.9 ± 2.2 | 0.009(2) | 2.95 ± 0.02 | 4.1 ± 0.7 | 4.25 ± 0.02 | 0.010(3) |
| 2.64 ± 0.03 | 5.7 ± 1.3 | |||||||
| Am (0.25 M HCl),46,* | –8.7 | 2.480 ± 0.002 | 10.3 ± 0.3 | 0.009 (fixed) | — | — | — | — |
| Am (0.11 M HO3SCF3),21 | –4.7 ± 0.9 | 2.48 ± 0.01 | 9.5 ± 0.9 | 0.0088(9) | — | — | — | — |
| Am (HNO3, 0.05 M) | –5.0 ± 1.0 | 2.47 ± 0.01 | 8.9 ± 0.8 | 0.008(1) | — | — | — | — |
| Am (HNO3, 4 M) | 2.1 ± 1.3 | 2.46 ± 0.01 | 6 (fixed) | 0.003(1) | 2.98 ± 0.04 | 1 (fixed) | 4.27 ± 0.04 | 0.003 (2) |
| 2.57 ± 0.03 | 2 (fixed) | |||||||
| 2.67 ± 0.02 | 2 (fixed) | |||||||
| Am (HNO3, 16 M) | 3.3 ± 0.8 | 2.50 ± 0.01 | 7.7 ± 0.8 | 0.005(1) | 2.97 ± 0.01 | 3.4 ± 0.7 | 4.26 ± 0.01 | 0.006(2) |
| 2.67 ± 0.01 | 5.4 ± 0.5 | |||||||
| Ac (0.11 M HO3SCF3),12 | –3.9 ± 1.0 | 2.63 ± 0.01 | 10.9 ± 0.5 | 0.009 (fixed) | — | — | — | — |
| Ac (HNO3, 0.05 M) | –2.9 ± 1.6 | 2.63 ± 0.02 | 10.0 ± 0.9 | 0.009 (fixed) | — | — | — | — |
| Ac (HNO3, 4 M) | 3.9 ± 2.0 | 2.61 ± 0.02 | 6 (fixed) | 0.006(4) | 3.24 ± 0.11 | 1 (fixed) | 4.42 ± 0.05 | 0.003 (5) |
| 2.75 ± 0.04 | 2 (fixed) | |||||||
| Ac (HNO3, 16 M) | 4.4 ± 2.1 | 2.70 ± 0.02 | 12.9 ± 4.0 | 0.012(4) | 3.20 ± 0.12 | 2.3 ± 1.7 | 4.42 ± 0.03 | 0.003(6) |
aAdditionally, σN2 was fixed to σO2 and CNterminal oxygen set to CNnitrogen. Data found in the literature and marked with an asterisk (*) had S02 values set to 1.