AN IMIDE ANION RADICAL THAT DIMERIZES AND ASSEMBLES INTO PI-STACKS IN SOLUTION

N,N'-Bis(4-phenysulfonate)-1,4,5,8-naphthalenetetracarboxylic diimide was prepared as the disodium and bis(tetrabutylammonium) salts. It was reduced electrochemically in DMF or water and by dithionite in water to a form an anion radical. On the basis of visible, NIR, IR, and ESR data, the anion radical is shown to be monomeric in DMF, dimeric in water, and aggregated in aqueous NaCl. The aggregates contain pi-stacks that are spectroscopically similar to the stacks found in a solid film of the anion radical.