Investigating the source of the electron in perylene and naphthalene diimides

Our group has been investigating the use of perylene bisimides and naphthalene diimides for the use in applications such as chromic displays and in organic photovoltaics. The suitability of these materials for such applications comes from the stable formation of a radical anion or dianion in water which can be created by the use of UV light or eletrochemically. Often these materials are used as oxygen sensors as the presence of the oxygen will oxidise, or prevent the formation of the radical. However, our materials do not have this sensitivity and our materials are used in air and non degassed water. The stability of this radical (spanning from hours to days depending on the formulation) has been attributed to the morphology or aggregate formed being able to stabilise or protect the radical from oxidation. One question we can not answer for these materials is where is the electron needed for the reduction of the material. Here we will use SANS to determine whether the structures present in solution are responsible for the formation of the radical, or whether the radical is coming from the solvent itself.