| Autor: |
Souvi, S. M., Tremblay, B., Perchard, J. P., Alikhani, M. E. |
| Předmět: |
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| Zdroj: |
Journal of Chemical Physics; 2/21/2009, Vol. 130 Issue 7, p074304, 10p, 1 Diagram, 3 Charts, 9 Graphs |
| Abstrakt: |
The formation of Pd2N2 from the cocondensation of effusive beams of Pd and N2 in neon and argon matrices is evidenced by absorptions in the range of 2200–1800 cm-1. In argon, selective irradiation in the near-infrared and visible ranges leads to interconversions between three structures, distinguished by the stretching frequency of the diatomic N2: Bridged T-shaped (νNN at 1990 cm-1), side on (νNN at 2178 cm-1) and parallel (νNN at 1823 cm-1). For the first two structures, the νNN mode is also accompanied by another signal below 500 cm-1. An extra feature close to 490 cm-1, not sensitive to irradiation at λirr>400 nm and also assignable to a molecule with the same Pd:N2 stoichiometry (2:1), corresponds to a centrosymmetrical Pd–N–N–Pd structure with an inactive νNN mode close to 2141 cm-1, as deduced from the observation of a weak signal close to 2630 cm-1 associated with this species and assignable to the combination νNN+νPdN. All these experimental data and their structural implications are fully supported by theoretical calculations [density functional theory (DFT)]. On the basis of this comparative study, we have obtained a reliable theoretical description of the spectroscopic data using the metageneralized gradient approximation functional within the unrestricted DFT (UDFT) formalism for all spin multiplets. We have also searched a stable electronic solution for each multiplet (particularly for the singlet state), in order to account for the nondynamic correlations. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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