| Autor: |
Willey, K. F., Yeh, C. S., Robbins, D. L., Pilgrim, J. S., Duncan, M. A. |
| Předmět: |
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| Zdroj: |
Journal of Chemical Physics; 12/15/1992, Vol. 97 Issue 12, p8886, 10p |
| Abstrakt: |
Mg+–H2O ion–molecule complexes are produced in a pulsed supersonic nozzle cluster source. These complexes are mass selected and studied with laser photodissociation spectroscopy in a reflectron time-of-flight mass spectrometer system. An electronic transition assigned as 2B2←X 2A1 is observed with an origin at 28 396 cm-1. The spectrum has a prominent progression in the metal-H2O stretching mode with a frequency (ω’e) of 518.0 cm-1. An extrapolation of this progression fixes the excited state dissociation energy (D’0) at 15 787 cm-1. The corresponding ground state value (D‘0) is 8514 cm-1 (24.3 kcal/mol). The solvated bending mode, and symmetric and asymmetric stretching modes of water are also active in the complex, as are the magnesium bending modes. A second electronic transition assigned as 2B1←X 2A1 is observed with an origin at 30 267 cm-1 and a metal stretch frequency for Mg+–H2O of 488.5 cm-1 (ΔG1/2). Spectra of both excited states are also observed for Mg+–D2O. Partially resolved rotational structure is analyzed for both isotopes, leading to the conclusion that the complex has a structure with C2v symmetry. This study was guided by ab initio calculations by Bauschlicher and co-workers, which provide accurate predictions of the electronic transition energies, vibrational constants, and dissociation energies. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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