Star-Shaped nanomolecules based on p-phenylene sulfide asterisks with a persulfurated coronene core

Persulfurated p-phenylene sulfide (PPS) molecular asterisks (6-9) from "generations" 1 to 4 were efficiently prepared. They represent a new class of electron-accepting PPS star-shaped nanomolecules. Spectroelectrochemistry, cyclic voltammetry and UV-visible studies were performed for the asterisks and for functionalized p-phenylene sulfide oligomers (1-4). These data confirmed for the first time that an electronic delocalization through the whole asterisk molecule exists in the radical anionic or dianionic forms, in spite of divalent sulfur bridges between phenyl groups. They could be seen as globular spheres with a three-dimensional electronic network and delocalization. Electrochemical studies indicated that sulfur substituents strongly stabilize the reduced form of the asterisk relative to coronene itself, and the ease of reduction depends on the PPS chain length.