Amphiphilic pyranines POCn (n = 8, 12, and 16) were synthesized, and their aggregation behaviors were investigated in water. (HNMR)-H-1 studies implied that POC16 existed in the conformation of the pyranine chromophore wrapped with a hexadecyl methylene chain, which showed no indication of aggregation at the concentration up to 10(-4) M. However, the formation of micelles was readily induced by the addition of methylviologen (MV2+) to a POC16 solution, which was responsible for an apparent large complexation constant of ca. 10(6)M(-1).