62480-45-9Relevant academic research and scientific papers
Optical Studies of a Simple Polyene Schiff Base: Low-Lying Electronic Levels in the Free, Hydrogen-Bonded, and Protonated Species
Palmer, Bruce,Jumper, Brian,Hagan, William,Baum, J. Clayton,Christensen, Ronald L.
, p. 6907 - 6913 (1982)
Fluorescence and fluorescence excitation spectra of a model polyene Schiff base, N-(2,4,6,8,10-dodecapentaenylidene)butylamine, have been obtained in 77 K hydrocarbon glasses.The low-energy electronic transitions of this polyene Schiff base have been studied in a variety of hydrogen-bonding and protonation environments.All spectra are well resolved and allow the accurate location of electronic origins.For all three species, i.e., free Schiff base, hydrogen-bonded Schiff base, and protonated Schiff base, the fluorescence origins are substantially red shifted (3108, 2774, and 2238 cm-1) from the origins of the strongly allowed absorptions.These experiments show that the lowest excited singlet in each of these Schiff base species correlates with the forbidden Ag- states observed in analogous polyene hydrocarbons.These findings are compared with current theoretical predictions and discussed with regard to their implications for the photochemistries of other polyene Schiff bases, including rhodopsin.
Vibronic coupling in polyenes: High resolution optical spectroscopy of a simple Schiff base
Girard, Mark,Arvidson, Eric,Christensen, Ronald
, p. 2265 - 2270 (1984)
High resolution fluorescence and fluorescence excitation spectra of a model polyene Schifl' base have been obtained. 4.2 K spectra of N-(2, 4, 6, 8,10-dodecapentaenylidine)butyl amine in n- tetradecane exhibit well-resolved electronic spectra (??*) from a single mixed crystal site.The major vibronic features, in common with those of polyene hydrocarbons, are due to combinations of symmetric carbon-carbon stretching vibrations.These are dominated by a double bond mode which decreases from 1589 to 1544 cm-1 upon electronic excitation.This decrease contrasts the 15 - 200 cm-1 increases seen in analogous polyene hydrocarbons.This diflerence is discussed in terms of vibronic coupling in a model previously applied to the hydrocarbons.
