| Autor: |
Asselin, P., Madebène, B., Soulard, P., Reinhardt, P., Alikhani, M. E. |
| Předmět: |
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| Zdroj: |
Journal of Chemical Physics; 6/28/2008, Vol. 128 Issue 24, p244301, 7p, 1 Diagram, 2 Charts, 4 Graphs |
| Abstrakt: |
For the first time the coexistence of a σ- and a π-complex in the C4H4O:HCl system has been observed, in the same supersonic expansion of a molecular jet seeded with argon (or helium) or in a flow-cooled cell at 240 K. This is an exception to the third of the Legon–Miller rules which claims the σ-structure to be the only one to exist. On the grounds of energetic considerations and band contour simulations, two observed bands at 2787.7 and 2795.5 cm-1 of the νs HCl stretching frequency are assigned to the two complexes, recorded as Fourier transform infrared spectra with a resolution between 0.2 and 0.5 cm-1. Complementary calculations show that the use of the standard second-order Mo\ller–Plesset perturbation theory may be erroneous for such a complex, due of the overestimation of the dispersion contribution with respect to the electrostatic term. It is finally established that only a balanced version of the second-order Mo\ller–Plesset perturbation method, spin-component scaled-MP2, or a higher level of theory like a coupled-cluster approach, can provide a reliable energetic analysis for this complex. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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