Rotationally resolved S-1-S-0 fluorescence excitation spectra of ethylbenzene, two conformers of n-propylbenzene, and two conformers of n-butylbenzene have been observed and assigned. The data obtained provide information about the equilibrium properties of each molecule, including their geometries in the S-1-S-0 states, their electronic distributions, and their dynamical behavior following the absorption of light. Trans structures are found to have S-1 states that are L-1(b) in character with relatively long fluorescence lifetimes. Gauche structures are found to have S-1 states that are mixed (L-1(b)/L-1(a)) in character with relatively short fluorescence lifetimes. Possible reasons for these differences in properties are discussed.