Coupled states in dinitrofluorene: relationships between ground state and excited state mixed valence.
The electronic absorption spectrum of 9,9-dimethyl-2,7-dinitrofluorene radical anion in HMPA displays both a NIR intervalence charge transfer and a visible excited state mixed valence transition. These transitions contain a similar vibronic progression resulting from molecular orbitals that are common to both transitions. Vibrational frequency and intensity data are acquired from the resonance Raman spectrum and used to calculate a best fit for the absorption spectrum. The normal coordinate distortions are analyzed in terms of the electronic changes for both transitions to explain their similarity. The Raman scattering intensity decreases at lower excitation wavelength as a result of Raman de-enhancement caused by interference between neighboring excited states.
Department of Chemistry and Biochemistry, University of California, Los Angeles , Los Angeles, California 90095, United States.
Matthew D
MD
Kiesz
Ryan M
RM
Hoekstra
Yen-Ting
YT
Chen
João P
JP
Telo
Stephen F
SF
Nelsen
Jeffrey I
JI
Zink