Radiative and nonradiative energy transfer between CO and pyrene involving higher excited states: A Spectroscopic Analysis

Abstract

A detailed spectroscopic analysis of radiative and nonradiative electronic energy transfer (EET) between CO and pyrene involving the higher electronically excited states is presented. Spectroscopic investigations on CO and pyrene that are codeposited in Ar matrices reveal that when CO is excited between 160 and 120 nm, into the A1π(ν')← X1S̀+ (ν″ = 0) vibronic transitions, fluorescence of pyrene occurs in addition to the radiative transitions in CO itself. A part of the EET from CO to pyrene is due to the radiative EET, which is confirmed from the modulation of the Cameron emission bands of CO between 200 and 250 nm by the excitation spectrum of pyrene in the same wavelength region. An evidence for nonradiative EET of Förster‐type is also obtained by investigating sandwich matrices with layers of Ar containing only pyrene and pyrene as well as CO. Present results are in line with those observed between CO and anthracene [Chem. Phys. Lett. 268, 169 (1997)].