TY - JOUR
T1 - Ultrafast Ring-Opening Reaction of 1,3-Cyclohexadiene
T2 - Identification of Nonadiabatic Pathway via Doubly Excited State
AU - Karashima, Shutaro
AU - Humeniuk, Alexander
AU - Uenishi, Ryuta
AU - Horio, Takuya
AU - Kanno, Manabu
AU - Ohta, Tetsuro
AU - Nishitani, Junichi
AU - Mitrić, Roland
AU - Suzuki, Toshinori
N1 - Funding Information:
This research was supported by JSPS KAKENHI Grant 15H05753, Mitsubishi Foundation, and the Japan-Belgium Research Cooperative Program between JSPS and F.R.S.-FNRS Grant JSBP120192201.
Publisher Copyright:
© 2021 American Chemical Society.
PY - 2021/6/2
Y1 - 2021/6/2
N2 - The photoinduced ring-opening reaction of 1,3-cyclohexadiene (CHD) to produce 1,3,5-hexatriene (HT) plays an essential role in the photobiological synthesis of vitamin D3 in the skin. This reaction follows the Woodward-Hoffmann rule, and C5-C6 bond rupture via an electronically excited state occurs with conrotatory motion of the end CH2 groups. However, it is noted that the photoexcited S1(π,π*) state of CHD is not electronically correlated with the ground state of HT, and the reaction must proceed via nonadiabatic transitions. In the present study, we have clearly observed the nonadiabatic reaction pathway via the doubly excited state of CHD using ultrafast extreme UV photoelectron spectroscopy. The results indicate that the reaction occurs in only 68 fs and creates product vibrational coherence. Extensive computational simulations support the interpretation of experimental results and provide further insights into the electronic dynamics in this paradigmatic electrocyclic ring-opening reaction.
AB - The photoinduced ring-opening reaction of 1,3-cyclohexadiene (CHD) to produce 1,3,5-hexatriene (HT) plays an essential role in the photobiological synthesis of vitamin D3 in the skin. This reaction follows the Woodward-Hoffmann rule, and C5-C6 bond rupture via an electronically excited state occurs with conrotatory motion of the end CH2 groups. However, it is noted that the photoexcited S1(π,π*) state of CHD is not electronically correlated with the ground state of HT, and the reaction must proceed via nonadiabatic transitions. In the present study, we have clearly observed the nonadiabatic reaction pathway via the doubly excited state of CHD using ultrafast extreme UV photoelectron spectroscopy. The results indicate that the reaction occurs in only 68 fs and creates product vibrational coherence. Extensive computational simulations support the interpretation of experimental results and provide further insights into the electronic dynamics in this paradigmatic electrocyclic ring-opening reaction.
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U2 - 10.1021/jacs.1c01896
DO - 10.1021/jacs.1c01896
M3 - Article
C2 - 34027664
AN - SCOPUS:85107711752
SN - 0002-7863
VL - 143
SP - 8034
EP - 8045
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 21
ER -