Selected interatomic distances (Å) and angles (°) in the η1:η2 and η2:η2 forms of 4 and comparison to the calculated structurea.
| η1:η2 | η2:η2 | ||
|---|---|---|---|
| Expt. | Calc. | ||
| Co(1)–O(1)/Co(3)–O(4) | 1.921(4) | 1.970(3) | 2.01 |
| Co(1)–O(2)/Co(3)–O(5) | 2.720(8) | 2.218(3) | 2.23 |
| Co(2)–O(2)/Co(4)–O(5) | 2.138(5) | 2.211(3) | 2.25 |
| Co(2)–O(3)/Co(4)–O(6) | 1.985(3) | 1.979(2) | 2.00 |
| C(1)–O(1)/C(2)–O(4) | 1.276(8) | 1.321(4) | 1.28 |
| C(1)–O(2)/C(2)–O(5) | 1.290(7) | 1.266(4) | 1.32 |
| C(1)–O(3)/C(2)–O(6) | 1.294(7) | 1.263(4) | 1.28 |
| O(1)–C(1)–O(2)/O(4)–C(2)–O(5) | 121.8(6) | 117.4(3) | 117.60 |
| O(2)–C(1)–O(3)/O(5)–C(2)–O(6) | 116.1(6) | 117.4(3) | 117.61 |
| O(3)–C(1)–O(1)/O(4)–C(2)–O(6) | 122.1(6) | 125.1(3) | 124.79 |
a
The optimized geometry with S = 3. The BP86/B1 (B1 = TZVP basis set on Co, O, N and carbonate C, and def2-SVP on the rest of the atoms) level of theory was used to model the η2:η2 conformer. See the ESI for computational details.