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Resonance Raman scattering from the metastable electronic state of an Na 2 [Fe(CN) 5 NO]·2H 2 O single crystal
Author(s) -
Krasser W.,
Woike Th.,
Haussühl S.,
Kuhl J.,
Breitschwerdt A.
Publication year - 1986
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/jrs.1250170118
Subject(s) - metastability , excited state , ground state , raman spectroscopy , excitation , atomic physics , chemistry , resonance (particle physics) , raman scattering , molecular physics , physics , optics , organic chemistry , quantum mechanics
Raman spectroscopy was used to characterize the extremely long duration metastable state of Na 2 [Fe(CN) 5 NO]·2H 2 O single crystals. By excitation with light of λ>540 nm only the Raman spectrum of the ground‐state configuration is obtained. With an excitation wavelength in the range 540–450 nm, the vibrational bands of the ground‐ and metastable‐state configurations are observed together with approximately equal intensities. In the wavenumber shift range 400–2200 cm −1 for each vibrational mode of the ground state a Raman band is found, but no splitting of degenerate modes appears. It is concluded that the symmetry of the molecule is not changed by pumping the metastable state. Excitation with light of λ=406.7 nm proves the existence of higher energetic states of the metastable configuration, which do not combine with the ground state. In addition to a thermal decay channel, there exists a further channel for depopulation of the metastable state using red light. Absorption spectroscopic measurements show the existence of an excited electronic state at 685 nm in the metastable configuration. This low‐lying energy level crosses with the first excited electronic level of the ground‐state configuration.