Table 9. ESP Charges Given for Atoms in the [4Fe–4S] Cluster, Its Coordinating Thiolates, and HMBPP from Two Representative Valence Isomers of the ROHP–EH(η2-ring) State When the [4Fe–4S] Cluster Reduced by One Electron Compared with the Charges from the Same Valence Isomers in the ROHP–EH(ROH) State When the [4Fe–4S] Cluster Is Oxidized50.
| ROHP–EH |
||||||
|---|---|---|---|---|---|---|
| αββα |
βααβ |
|||||
| ox | red (η2-ring) | Δqa | ox | red (η2-ring) | Δqa | |
| FE1 | 0.404 | 0.373 | –0.030 | 0.404 | 0.307 | –0.097 |
| FE2 | 0.490 | 0.533 | 0.043 | 0.491 | 0.512 | 0.021 |
| FE3 | 0.599 | 0.645 | 0.045 | 0.599 | 0.692 | 0.093 |
| FE4 | 0.477 | 0.515 | 0.038 | 0.477 | 0.494 | 0.018 |
| sum | 1.969 | 2.065 | 0.096 | 1.970 | 2.005 | 0.035 |
| S1 | –0.440 | –0.583 | –0.143 | –0.440 | –0.592 | –0.152 |
| S2 | –0.302 | –0.328 | –0.026 | –0.302 | –0.267 | 0.035 |
| S3 | –0.412 | –0.597 | –0.186 | –0.412 | –0.570 | –0.158 |
| S4 | –0.600 | –0.740 | –0.140 | –0.600 | –0.691 | –0.091 |
| sum | –1.753 | –2.248 | –0.495 | –1.754 | –2.119 | –0.365 |
| C12 | –0.267 | –0.396 | –0.129 | –0.268 | –0.346 | –0.078 |
| C96 | –0.332 | –0.434 | –0.102 | –0.332 | –0.398 | –0.066 |
| C197 | –0.393 | –0.486 | –0.093 | –0.393 | –0.460 | –0.068 |
| sum | –0.993 | –1.316 | –0.324 | –0.993 | –1.205 | –0.212 |
| total cluster | –0.777 | –1.499 | –0.723 | –0.777 | –1.319 | –0.542 |
| OC4 | –0.119 | –0.309 | –0.189 | –0.119 | –0.328 | –0.209 |
| C3 | –0.036 | –0.016 | 0.020 | –0.035 | –0.038 | –0.003 |
| C2 | –0.142 | 0.049 | 0.191 | –0.142 | 0.068 | 0.210 |
| total HMBPP | –0.430 | –0.636 | –0.205 | –0.430 | –0.784 | –0.354 |
| cluster + HMBPP | –1.207 | –2.135 | –0.928 | –1.207 | –2.103 | –0.896 |
a
The difference in charge (Δq) between the oxidized and 1e– reduced atoms is indicated.