Ultrafast decay dynamics of N-ethylpyrrole excited to the S-1 electronic state: A femtosecond time-resolved photoelectron imaging study

N -ethylpyrrole is one of ethyl-substituted derivatives of pyrrole and its excited-state decay dynamics has never been explored. In this work, we investigate ultrafast decay dynamics of N - ethylpyrrole excited to the S-1 electronic state using a femtosecond time-resolved photoelectron imaging method. Two pump wavelengths of 241.9 and 237.7 nm are employed. At 241.9 nm, three time constants, 5.0 & PLUSMN;0.7 ps, 66.4 & PLUSMN;15.6 ps and 1.3 & PLUSMN;0.1 ns, are derived. For 237.7 nm, two time constants of 2.1 & PLUSMN;0.1 ps and 13.1 & PLUSMN;1.2 ps are derived. We assign all these time constants to be associated with different vibrational states in the S1 state. The possible decay mechanisms of different S-1 vibrational states are briefly discussed.