The fluorene-Ar-4 cluster has been shown to exhibit two distinct isomers when formed in a molecular beam. Resonance enhanced multiphoton ionization and mass analyzed threshold ionization experiments have been performed to investigate the structural properties, energetics and dynamics of these clusters when excited to vibronic bands in the S-1 electronic state, with a specific interest in measuring isomer interconversion. At 208 cm(-1) excess energy in the S-1 isomer interconversion is not observed in the Ar-4 cluster. Dissociation of the Ar-5 cluster from the 722 cm(-1) band is shown to produce both Ar-4 isomers.