An experimental test of C-N bond twisting in the TICT state: syn-anti photoisomerization in 2-(N-methyl-N-isopropylamino)-5-cyanopyridine.
A previously untested essential consequence of the "TICT" (twisted internal charge transfer) interpretation of the nature of the "anomalous" excited state of p-dimethylaminobenzonitrile (1) and related compounds has now been verified: at -90 degreesC, the dual fluorescence of a desymmetrized analogue, 2-(N-methyl-N-isopropylamino)-5-cyanopyridine (2), in methanol (MeOH) is accompanied by syn-anti isomerization around the C-N bond, whereas its ordinary fluorescence in tetrahydrofuran is not.
Dobkowski
Jacek
J
Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44, 01-224 Warsaw, Poland.
Wójcik
Jacek
J
Koźmiński
Witold
W
Kołos
Robert
R
Waluk
Jacek
J
Michl
Josef
J