Flexible methylene containing N,N'-bis-(benzyl)-3,4,9,10-perylenebis(dicarboximide) (1) was synthesized. Self-assembled microstructures (hollow tubes, average length and width: 7.7 and 0.8 μm) of 1 were also prepared (T-1). Comparative studies of the optical, thermal and electrochemical properties of 1 and T-1 have been extensively carried out. The T-1 hallow tubes have shown extremely broad absorption in the near-infrared (300-800 nm) region (NIR) even in solution and intensified conductivity in the solid-state compared to 1. Under daylight and a UV lamp (365 nm), the emission colors of 1 are uniform pink and fluorescent yellow, respectively. Under the same conditions the colors of T-1 change to deep brown and glowing red, respectively. Two different isopotential points obtained through CV scans for 1 indicate the presence of two interconvertible chromophores within the system. The results clearly indicate that the anodic and cathodic processes are extremely intensified in the self-assembled T-1 structure.

The present investigation describes for the first time, the synthesis and detailed characterization of a novel fluorescent and amphiphilic chitosan polymer (3) containing fluorescent peryleneimide chromophores for biomedical applications. The polymer 3 is moderately soluble in a wide range of organic solvents and aqueous solutions, unlike chitosan (2). The Mw of 3 and 2 determined by GPC were 467 kDa and 460 kDa, respectively. The photophysical and electrochemical properties measured in solution and solid states are engrossing. is soluble in the entire pH range and exhibits excimer emission above pH 5. In solution, 3 is electroactive but 2 is not. Whereas in the solid-state, 3 shows one quasi-reversible oxidation and reversible reduction step and 2 exhibits only one quasi-reversible oxidation step. Our results point out a new class of organic biopolymers that could yield promising potentials in many biomedical applications.