Table 2.
Mössbauer isomer shift and electric quadrupole splitting for some four-, five- and six-coordinate high-spin iron(II) compounds.
| Compound | Ligands | δ (mm/s) | ΔEQ (mm/s) | T (K) | Reference |
|---|---|---|---|---|---|
| Fe-Az | 2N,O,S | 0.90 | -3.17 | 80 | this work |
| C9S rubredoxin | 4S | 0.70 | -3.25 | 4.2 | 68 |
| C42S rubredoxin | 3S,O | 0.79 | -3.27/+2.95a | 4.2 | 69 |
| desulfoferrodoxin, | 74, 78 | ||||
| center I | 4S | 0.69 | 3.51 | 4.2 | |
| center II | 4N,S | 1.04 | 2.87 | 4.2 | |
| neelaredoxin | 4N,S | 1.02 | 2.80 | 4.2 | 79,80 |
| [FeII(cyclam)(tdt)]b | 4N,2S | 1.00 | +3.55 | 80 | 75 |
| Fe-Az(M121A) | 2N,O,S | 0.88 | 2.90 | 80 | this work |
| Fe-Az(M121A)-N3 | 3N,O,S | 1.02 | 2.74 | 80 | this work |
| Fe-Az(M121A)-CN | 2N,O,C,S | 0.37 | 0.70 | 80 | this work |
| [(TPP)Fe-CN]–c | 4N,C | 0.36 | 1.83 | 100 | 81 |
| [(TPP)(MeIm)Fe-CN]–c | 5N,C | 0.37 | 0.61 | 100 | 81 |
| cis-(phen)2Fe(CN)2 | 4N,2C | 0.18d | 0.58 | 298 | 82 |
a
Two forms were observed.
b
tdt = toluenedithiolate.
c
TPP = tetraphenylporphyrin; MeIm = 1-methylimidazole.
d
The value measured at room temperature is expected to be roughly 0.1 mm/s higher at 80 K due to the second-order Doppler shift.