ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
This paper presents photodissociation spectra for the solvated metal ion clusters Sr+(NH3)1,2 and Sr+(H2O)1,2 from 420 to 740 nm in the visible region of the spectrum. The spectra have a banded structure, corresponding to transitions from ground electronic states based upon the 2S configuration of the Sr+ ion to excited states based primarily upon p-orbitals of the excited Sr+. The photodissociation cross sections are large, ∼10−17–10−16 cm2. For the same solvent, spectral band positions are only weakly dependent upon the degree of solvation. We show that a dramatic reduction in intensity of the second excited state band in the Sr+(NH3)2 spectrum suggests that this state has strong atomic ion d-orbital parentage and that the molecule is centrosymmetric. Photodissociation of the H2O solvated species proceeds through three excited electronic states corresponding principally to three different orientations of the metal p orbitals with respect to solvent symmetry axis. Absorption band positions for Sr+(H2O)2 are shifted slightly from those of Sr+(H2O) and the presence of a substantial unstructured continuum appears in the doubly solvated ion. The absorption spectra for the Sr+(H2O)1,2 species are significantly blue-shifted and narrowed relative to those of Sr+(NH3)1,2, an observation that is understood through simple molecular orbital diagrams incorporating the fact that the ionization potential of H2O is 2.4 eV larger than that of NH3.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.459755
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