TY - JOUR
T1 - On the condensed phase ring-closure of vinylheptafulvalene and ring-opening of gaseous dihydroazulene
AU - Schalk, Oliver
AU - Broman, Søren L.
AU - Petersen, Michael Å
AU - Khakhulin, Dmitry V.
AU - Brogaard, Rasmus Y.
AU - Nielsen, Mogens Brøndsted
AU - Boguslavskiy, Andrey E.
AU - Stolow, Albert
AU - Sølling, Theis I.
PY - 2013/4/25
Y1 - 2013/4/25
N2 - Dihydroazulenes are interesting because of their photoswitching behavior. While the ring-opening to vinylheptafulvalene (VHF) is light induced, the back reaction is known to proceed thermally. In the present paper, we show the first gas phase study of the ring-opening reaction of 2-phenyl-1,8a-dihydroazulene-1, 1-dicarbonitrile (Ph-DHA) by means of time-resolved photoelectron spectroscopy which permits us to follow the ring-opening process. Moreover, we investigated s-trans-Ph-VHF in a series of transient absorption experiments, supported by ab initio computations, to understand the origin of the absence of light-induced ring-closure. The transient absorption results show a biexponential decay governed by a hitherto unknown state. This state is accessed within 1-2 ps and return to the ground state is probably driven through a cis-trans isomerization about the exocyclic C1=2 double bond. The rapid decrease in potential energy disfavors internal rotation to s-cis-Ph-VHF, the structure that would precede the ring-closure reaction.
AB - Dihydroazulenes are interesting because of their photoswitching behavior. While the ring-opening to vinylheptafulvalene (VHF) is light induced, the back reaction is known to proceed thermally. In the present paper, we show the first gas phase study of the ring-opening reaction of 2-phenyl-1,8a-dihydroazulene-1, 1-dicarbonitrile (Ph-DHA) by means of time-resolved photoelectron spectroscopy which permits us to follow the ring-opening process. Moreover, we investigated s-trans-Ph-VHF in a series of transient absorption experiments, supported by ab initio computations, to understand the origin of the absence of light-induced ring-closure. The transient absorption results show a biexponential decay governed by a hitherto unknown state. This state is accessed within 1-2 ps and return to the ground state is probably driven through a cis-trans isomerization about the exocyclic C1=2 double bond. The rapid decrease in potential energy disfavors internal rotation to s-cis-Ph-VHF, the structure that would precede the ring-closure reaction.
UR - https://www.scopus.com/pages/publications/84876839816
U2 - 10.1021/jp400616c
DO - 10.1021/jp400616c
M3 - Article
C2 - 23556480
AN - SCOPUS:84876839816
SN - 1089-5639
VL - 117
SP - 3340
EP - 3347
JO - Journal of Physical Chemistry A
JF - Journal of Physical Chemistry A
IS - 16
ER -