Concentration-dependent molecular dynamics of long coil-rod-coil molecules at the concentrations of 1 x 10(-6) M similar to 1 x 10(-4) M in polar or non-polar solvent were investigated by steady-state excitation, fluorescence, and picosecond time-resolved fluorescence spectroscopies. The fluorescence spectra of the molecules reveal both characteristics of local excited-state emission and strong intramolecular charge-transfer (ICT) emission. The steady-state excitation spectra and the picosecond time-resolved fluorescence decay profiles in the concentrations of 5 x 10(-5) M and 1 x 10(-4) M ascertain hydrophobic rod-to-rod interaction (J-aggregation) in methanol solution. The hydrophilic intermolecular interactions (amorphous aggregation) in n-hexane are also discussed.