In this paper, we report that a 1,7-bis-pyridinoyl perylene diimide amphiphile undergoes distinctly different self-assembly in methanol compared to ethanol. This amphiphile forms hollow nanospheres in methanol, whereas in ethanol, it self-assembles into microrose flowers which consist of several soft nano-plates packing like rose petals. Studies of the concentration-dependent absorption spectra confirmed this solvent effect. The most distinct spectral features were the A(0-0)/A(0-1) and A(0-0)/A(s0-s2) values. These spectral changes were explained in terms of the Franck-Condon factors. (C) 2010 Elsevier Inc. All rights reserved.