Table 2.
Experimental and DFT-computed frequencies (in cm−1) of the relevant corrin-based vibrational modes depicted in Fig. 5. The isotopic shifts for H/D exchange at C10 are given in parentheses; their estimated error is ±1 cm−1.
| νs (#1) | νs (#2) | ν as | νs (#3) | ||
|---|---|---|---|---|---|
| Free Co(II)Cbl | Exp. | 1482 (− 6) | 1529 (− 3) | 1555 (− 9) | 1587 (− 2) |
| Calc. | 1487.4 (− 4.9) | 1530.0 (− 2.3) | 1556.8 (− 5.7) | 1584.9 (− 0.6) | |
|
| |||||
| Free Co(II)Cbi+ | Exp. | 1486 (− 4) | 1533 (− 6) | 1564 (− 6) | 1594 (0) |
| Calc. | 1485.2 (− 4.7) | 1528.1 (− 2.0) | 1557.1 (− 5.5) | 1584.2 (− 0.9) | |
|
| |||||
| Four-coordinate Co(II)rrinoids | Co(II)Cbl | 1493 | 1533 | 1561 | 1592 |
| Co(II)Cbi+ | 1491 | 1535 | 1564 | 1591 | |
| Calc. | 1490.6 (− 5.0) | 1528.1 (− 2.2) | 1558.2 (− 5.1) | 1584.6 (− 1.1) | |