Table 1.
Spectroscopic data elucidating the binding and cleavage of O2. Overview of the experimentally and theoretically obtained data for the bdpdz (1 a) and bdptz (1 b) systems after oxygenation, leading to the corresponding Cu2O (2 a/b) or Cu4O2 (3 a/b) complexes.
|
|
Cu2O |
|
Cu4O2 [b] |
|||||||
|---|---|---|---|---|---|---|---|---|---|---|
|
Absorption feature |
TDDFT [a] |
2 a‐PF6 |
2 a‐OTf |
2 b‐PF6 |
2 b‐OTf |
|
3 a‐PF6 |
3 a‐OTf |
3 b‐PF6 |
3 b‐OTf |
|
λ [nm] (ϵ [m −1 cm−1]) |
390/380 |
370 (2739) |
371 (2391) |
368 (2488) |
370 (2642) |
|
397 (1956) |
398 (2754) |
393 (2150) |
390 (2770) |
|
431/434 |
421 (1282) |
422 (1119) |
417 (1343) |
421 (1350) |
|
N.A. |
N.A. |
N.A. |
N.A. |
|
|
554+701/572 |
630 (264) |
630 (219) |
633 (207) |
630 (213) |
|
619 (200) |
613 (160) |
619 (168) |
621 (222) |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Vibrational mode (Δ18O2) [cm−1] |
DFT [c] |
2 a‐PF6 |
2 a‐OTf |
2 b‐PF6 |
2 b‐OTf |
|
DFT [d] |
3 a‐PF6 |
3 b‐PF6 |
3 b‐OTf |
|
ν Cu−O [e] |
563 (35)/ 587 (29) |
629 (23) |
619 (11) |
623 (20) |
619 (8) |
|
523 (28)/ 534 (27) |
607 (14) |
607 (16) |
604 (8) |
|
ν O−O |
N.A. |
N.A. |
N.A. |
N.A. |
N.A. |
|
854 (50)/ 849 (49) |
854 (62) |
854 (52) |
855 (57) |
General remarks: Solvent: acetone; oxygenations were carried out at least duplicate; values presented here are averaged; c=0.6–1.0 mm. [a] Values are given as follows: 2 a (bdpdz)/2 b (bdptz). Based on the assumption that acetone is the coordinating solvent; values with acetonitrile instead of acetone can be found in Table S9. DFT: B3LYP/def2‐TZVP(‐f). [b] The given molar absorption coefficients at these maxima are based on the assumption that the species is tetranuclear. [c] Based on the assumption that acetone is the coordinating solvent; values without acetone or with acetonitrile can be found in Table S9. DFT: PBE‐D3(BJ)/def2‐SVP. Detailed assignments as well as schematic representations of the vibrational modes can be found in Section S6.1. [d] Calculations were performed without any coligands like acetone or acetonitrile. 1 a: d O–O=1.412 Å and 1 b: d O–O=1.414 Å. DFT: PBE‐D3(BJ)/def2‐SVP. Detailed assignments as well as schematic representations of the vibrational modes can be found in Section S6.1. [e] ν Cu−O=νas Cu−O; ν s Cu−O not observed.