TY - JOUR
T1 - Delocalization of free electron density through phenylene-ethynylene
T2 - Structural changes studied by time-resolved infrared spectroscopy
AU - Polyansky, Dmitry E.
AU - Danilov, Evgeny O.
AU - Voskresensky, Sergey V.
AU - Rodgers, Michael A.J.
AU - Neckers, Douglas C.
PY - 2005/10/5
Y1 - 2005/10/5
N2 - We have studied the photochemistry of 1,4-bis(2-[4-tert-butylperoxycarbonylphenyl]ethynyl)benzene (1) and tert-butyl 4-(2-{4-[2-(4-phenyloxycarbonylphenyl)-1-ethynyl]phenyl}-1-ethynyl)peroxybenzoate (2). Excitation of 1 and 2 by a 355-nm laser pulse leads to the rapid formation of aroyloxyl radicals. An unpaired electron conjugated with the phenylene-ethynylene core is substantially delocalized over the π-system of the chromophore. The -C≡C- vibrational frequencies of these radicals are red-shifted relative to 1 and 2 as measured by time-resolved IR spectroscopy. This shift is attributed to the change in the triple bond character due to delocalization of the free electron.
AB - We have studied the photochemistry of 1,4-bis(2-[4-tert-butylperoxycarbonylphenyl]ethynyl)benzene (1) and tert-butyl 4-(2-{4-[2-(4-phenyloxycarbonylphenyl)-1-ethynyl]phenyl}-1-ethynyl)peroxybenzoate (2). Excitation of 1 and 2 by a 355-nm laser pulse leads to the rapid formation of aroyloxyl radicals. An unpaired electron conjugated with the phenylene-ethynylene core is substantially delocalized over the π-system of the chromophore. The -C≡C- vibrational frequencies of these radicals are red-shifted relative to 1 and 2 as measured by time-resolved IR spectroscopy. This shift is attributed to the change in the triple bond character due to delocalization of the free electron.
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U2 - 10.1021/ja053120l
DO - 10.1021/ja053120l
M3 - Article
C2 - 16190681
AN - SCOPUS:25844461398
VL - 127
SP - 13452
EP - 13453
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 39
ER -