Synthesis and electroactive properties of poly(amidoamine) dendrimers with an aniline pentamer shell

Poly(amidoamine) (PAMAM) dendrimers with different generations (G = 2, 3 and 4) were synthesized, peripherally modified with aniline pentamers and studied for their redox and dopable behavior under different pH conditions. It was found that the electron transition of the pi(B)-pi(Q) band red-shifted and the size of PAMAM G2 decreased in an alkaline medium. The chemical oxidation process and the color change of these modified dendritic macromolecules were measured by cyclic voltammetry (CV) and electrochromism. All of the dendrimers showed three redox peaks in the CV. The current density of the voltammograms increased with increasing the number of aniline pentamer segments at the periphery. A drastic color change was observed when a linear potential sweep was applied. The thermal properties of the electroactive dendrimers were evaluated by differential scanning calorimetry and thermogravimetric analysis.