The Nitrogen-Laser Excited Luminescence of Pyrene: A Student Laboratory Study of Excimer Dynamics

An Undergraduate laboratory experiment that uses a nitrogen laser to produce the first excited singlet state of pyrene is described. The resulting luminescence is studied as a function of wavelength, time, and pyrene concentration to observe the dynamics of both the excited pyrene monomer and the pyrene excimer. The initial rise and subsequent decay of the excimer is directly observed. Data is analyzed in terms of coupled rate equations, and students obtain four different rate constants in interactive calculations. The apparatus is relatively easy to set up, and introduces students to a variety of topics in photochemical kinetics and fast measurement techniques.