Absorption and fluorescence spectra of 1-, 2-and 4-fluorenamides (1-FAm, 2-FAm, 4-FAm) were studied in different solvents and at various acid concentrations. This study indicates that the long wavelength absorption band is long-axis polarised in 2-FAm whereas in 1-FAm and 4-FAm, it is composed of long-and short-axis polarised transitions. The-CONH2 group in 1-FAm and 4-FAm is coplanar with the fluorene moiety, whereas the same group in 2-FAm ...
