Photo-impulsive reactions in the electronic ground state without electronic excitation: non-photo, non-thermal chemical reactions.
Allyl phenyl ether has an absorption band in the ultraviolet region (λ < 400 nm); therefore, irradiation with few-optical-cycle ultraviolet pulses (λ = 360-440 nm) causes a transition to the ultraviolet band, which leads to an electronic state and a photo-Claisen rearrangement (radical reaction) in the electronic excited state. However, the reaction scheme of allyl phenyl ether under irradiation with few-optical-cycle visible pulses (λ = 525-725 nm) was determined to be same as that of the thermal Claisen rearrangement ([3,3]-sigmatropic rearrangement), which is symmetry-allowed in the electronic ground state. Photo-excitation with few-optical cycle visible pulses below the absorption band induces a photo-impulsive reaction in the electronic ground state without electronic excitation, of which the trigger scheme is different from that of photoreaction or thermal-reaction. The photo-impulsive reaction in the electronic ground state is highly possible as a novel reaction scheme.
Innovative use of light and materials/life, PRESTO, JST, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan. iwakura@ils.uec.ac.jp
Izumi
I
Iwakura
Atsushi
A
Yabushita
Jun
J
Liu
Kotaro
K
Okamura
Takayoshi
T
Kobayashi