FLUORESCENCE AND DOLE BURNING DEPLETION SPECTRA OF JET-COOLED 1-ANTHRYL)-3-(M-(N,N-DIMETHYLAMINO)PHENYL)PROPANES AND 9-ANTHRYL)-3-(M-(N,N-DIMETHYLAMINO)PHENYL)PROPANES - MULTICONFORMATIONS AND EXCIPLEX FORMATION
M. Kurono et al., FLUORESCENCE AND DOLE BURNING DEPLETION SPECTRA OF JET-COOLED 1-ANTHRYL)-3-(M-(N,N-DIMETHYLAMINO)PHENYL)PROPANES AND 9-ANTHRYL)-3-(M-(N,N-DIMETHYLAMINO)PHENYL)PROPANES - MULTICONFORMATIONS AND EXCIPLEX FORMATION, Journal of physical chemistry, 99(24), 1995, pp. 9668-9674
Fluorescence excitation and hole burning depletion spectra of jet-cool
ed bichromophoric compounds, 1-(9- and 1-anthryl)-3-(m-(N,N-dimethylam
ino)phenyl)propanes (9-An-m-DMA and 1-An-m-DMA), indicate that two iso
meric conformations of these compounds are involved in the ground stat
e. Two distinct conformers (9a and 9b) of 9-An-m-DMA exhibit roughly e
qual intensity of excitation spectra, while one conformer is major (1a
) and another is minor (1b) in 1-An-m-DMA. These ground-state conforme
rs exhibit remarkably different excess vibrational energy (Delta E) de
pendence of the intramolecular charge transfer in the singlet excited
state: the Delta E dependence of the exciplex fluorescence and decay t
imes are considerably different between the two conformations. The fac
ts seem attributable to the torsional conformation of the m-(N,N-dimet
hylamino)phenyl moiety concerning the trimethylene (An-C-1-C-2-C-3-m-D
MA) of these compounds in the ground state, from which the geometrical
transformations take place to the favorable conformers' for the intra
molecular charge transfer.