Investigation of ultrafast excited-state dynamics of 3-furfural

3-Furfural(C5H4O2) is a furan(C4H4O) derivative compound formed by replacing the hydrogen (H) atom at the ring 3-position with the aldehyde (CHO) group substituent. In this work, we intend to investigate the ultrafast decay dynamics of electronically excited 3-furfural using the femtosecond time-resolved photoelectron imaging technique. At pump wavelengths of 259.5, 238.6 and 218.3 11m, two alternative decay mechanisms for the S2(1ππ*) state are tentatively proposed and discussed. Specifically, we prefer to suggest that a fraction of the initially prepared wavepacket in the S2(1ππ*) state is likely to undergo the subpicosecond relaxation via the S1(1nπ*) state. Presumably the lower lying T2(3ππ*) state is subsequently populated on a ∼4 ps timescale via intersystem crossing from the minimum of the S1(1nπ*) state surface. The relaxation of the T2(3ππ*) state is sensitive to its vibrational excess energy and the value of its lifetime is 1.6±0.2 ns, 280±30 ps and 50±10 ps for pump wavelengths of 259.5, 238.6 and 218.3 m, respectively.