Excited-state lifetime of adenine near the first electronic band origin

摘要

The excited-state lifetime of supersonically cooled adenine was measured in the gas phase by femtosecond pump-probe transient ionization as a function of excitation energy between 36 100 and 37 500 cm~(-1). The excited-state lifetime of adenine is ～2 ps around the 0-0 band of the L1 b π π state (36 105 cm~(-1)). The lifetime drops to ～1 ps when adenine is excited to the L1 a π π state with the pump energy at 36 800 cm ~(-1) and above. The excited-state lifetimes of L1 a and _(L1 b) π π states are differentiated in accordance with previous frequency-resolved and computational studies.