A systematic investigation of the effects of stereochemistry and solid-state morphology on emission characteristics were performed using glass-forming pyrenyl and carbazolyl derivatives as neat films in PMMA and cholesteric liquid crystalline glass. At high dilution in tetrahydrofuran, pyrenyl derivatives were prone to form intramolecular excimers whereas carbazolyl derivatives showed no evidence for excimers. Both pyrenyl and carbazolyl derivatives at 10(-3) to 10(-2) M in isotropic and ordered solid hosts exhibited mostly monomer emission. In neat films, intermolecular excimers prevailed in pyrenyl derivatives whereas carbazolyl derivatives showed evidence for monomer emission as well. One feature that distinguishes carbazolyl derivatives from poly(N-vinylcarbazole) is the observed fine structures:in the fluorescence spectra of thin films. Order parameters characterizing the helical alignment of pyrenyl and carbazolyl pendants with a cholesteric host were determined with circularly polarized fluorescence spectroscopy. The results indicate the relative ease of aligning pyrenyl groups, presumably because of the more favorable regiochemistry and conformational flexibility.