Table 1.
Metric parameters (in Å) for the donor-acceptor (OO) and donor-proton (OH) contacts in the monomers and dimers of 3 and 4. The CPMD results are given as: Average ± standard deviation.
| Compound | Method | Bridge 1 | Bridge 2 | ||||
|---|---|---|---|---|---|---|---|
| d(OH) | d(OO) | d(OH) | d(OO) | OHO[°] | COH…O[°] | ||
| 3, monomer | CPMD | 0.993 ± 0.022 | 2.728 ± 0.151 | - | - | - | - |
| 3, dimer | - | 1.027 ± 0.032 | 2.634 ± 0.095 | 1.028 ± 0.034 | 2.633 ± 0.091 | - | - |
| 4, monomer | - | 1.005 ± 0.022 | 2.587 ± 0.088 | - | - | - | - |
| 4, dimer | - | 1.028 ± 0.036 | 2.650 ± 0.122 | 1.028 ± 0.037 | 2.653 ± 0.115 | - | - |
| 3, monomer | DFT | 0.978 | 2.670 | - | - | 150.2 | 64.4 |
| 3, dimer | - | 0.999 | 2.679 | 1.001 | 2.660 | 178.9 | 0.2 |
| 4, monomer | - | 0.985 | 2.583 | - | - | 160.0 | 50.1 |
| 4, dimer | - | 1.000 | 2.669 | 0.999 | 2.679 | 178.6 | 0.7 |
| 3, dimer | X-ray [38] | 0.84 | 2.698 | 0.84 | 2.698 | 155.5 | - |
| 3, oligomer | - | 0.84 | 2.681 | - | - | - | - |