The vibrational structures of jet-cooled 2-phenylanthracene, 9-vinylanthracene, and 9-(2-naphthyl)anthracene have been investigated by laser-induced fluorescence in the frequency range 29900–27600 cm-1. For each molecule the excitation spectrum contains a progression that can be assigned to an excited-state mode corresponding primarily to torsional motion about the bond joining the anthracene ring to the substituent. The experimentally observed vibrational spacings for this mode are modeled well by a simple one-dimensional effective potential in the torsional angle ϕ, of the form V(ϕ) =1/2ΣnVn(1 - cos nϕ). The best-fit potential parameters for the molecule are the following: 2-phenylanthracene, V2= 864 cm-1and V4= -77 cm-1; 9-vinylanthracene, V2= 1909 cm-1and V4= -106 cm-1; and 9-(2-naphthyl)anthracene, V2= -1087 cm-1and V4= -1000 cm-1. However, a comparison of observed vibronic intensities and isotope shifts in the vibrational spacings with those predicted for pure torsional motion shows that the simple one-dimensional-model potential is not completely adequate.