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

Abstract

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. © 2010 American Institute of Physics.