Table 7.
The A-A’ atomic energy terms of C = O in various chemical environments (kJ/mol). The average values are given in the last two rows, with the standard deviation in brackets. Method: 2PDM-M/CCSD(T)/uncontracted 6–31 + G(d, p). Grid (15,15). The sum is a sum of the absolute energies. The final three columns on the right give the energies relative to those of acetaldehyde and of acetone (in brackets)
| Molecule | C | O | sum | C | O | sum |
|---|---|---|---|---|---|---|
| CH2O | 122.6 | 194.0 | 316.6 | −8.2 (−16.0) | −2.8 (−6.5) | 11.0 (22.5) |
|
CH3CHO (reference molecule) |
130.8 | 196.8 | 327.6 | 0.0 (−7.7) | 0.0 (−3.7) | 0.0 (11.5) |
| C2H5CHO | 132.2 | 196.7 | 328.9 | 1.4 (−6.4) | −0.1 (−3.9) | 1.5 (10.2) |
| n-C3H7CHO | 132.2 | 197.3 | 329.5 | 1.3 (−6.4) | 0.5 (−3.2) | 1.8 (9.6) |
| iso-C3H7CHO | 133.0 | 198.2 | 331.2 | 2.1 (−5.6) | 1.4 (−2.3) | 3.6 (7.9) |
|
CH3C(O)CH3 (2nd ref. molecule) |
138.6 | 200.5 | 339.1 | 7.7 (0.0) | 3.7 (0.0) | 11.5 (0.0) |
| CH3C(O)C2H5 | 139.2 | 199.6 | 338.9 | 8.4 (0.6) | 2.9 (−0.9) | 11.3 (1.5) |
| HC(O)NH2 | 123.9 | 189.6 | 313.5 | −6.9 (−14.7) | −7.2 (−10.9) | 14.1 (25.6) |
| CH3C(O)NH2 | 131.6 | 193.3 | 324.9 | 0.8 (−6.9) | −3.5 (−7.2) | 4.3 (14.2) |
| HC(O)N(H)CH3 | 126.8 | 191.2 | 317.9 | −4.1 (−11.8) | −5.6 (−9.3) | 9.7 (21.2) |
| CH3C(O)N(H)CH3 | 134.1 | 194.1 | 328.2 | 3.3 (−4.5) | −2.7 (−6.4) | 5.9 (10.9) |
| HCO2H | 126.9 | 193.0 | 319.9 | −3.9 (−11.7) | −3.8 (−7.5) | 7.8 (19.2) |
| HCO2− | 130.2 | 192.8 | 323.0 | −0.6 (−8.3) | −4.0 (−7.8) | 4.6 (16.1) |
| CH3CO2H | 135.7 | 196.9 | 332.7 | 4.9 (−2.9) | 0.1 (−3.6) | 5.0 (6.4) |
| CH3CO2− (conf. A)a | 134.7 | 194.7 | 329.4 | 3.8 (−3.9) | −2.1 (−5.9) | 6.0 (9.8) |
| CH3CO2− (conf. B) | 135.5 | 194.7 | 330.1 | 4.6 (−3.1) | −2.1 (−5.8) | 6.7 (9.0) |
| CHOCH2OH | 133.7 | 196.7 | 330.4 | 2.8 (−4.9) | 0.0 (−3.8) | 2.9 (8.7) |
| Average (SD) | 131.9 (4.5) | 195.3 (2.8) | 327.2 (6.9) | 1.6 (4.0) | −1.4 (2.9) | 6.0 (3.8) |
aFor acetate we consider two conformations: A with the unique methylic hydrogen in the CO2plane, and B with this hydrogen at right angles to the CO2plane, both with Cs symmetry. For conformation A, the different C-O lengths have been averaged