Charge transfer complexes in polysilsesquioxane gels: a supramolecular approach

Abstract

Polysilsesquioxane gels based on naphthalene diimides (NDI-PS) exhibit unique electrochemical, photochemical and binding properties towards pi-donor molecules (D). The latter can potentially be entrapped within the 3D-network of NDI-PS gels through hydrogen-bonding and though charge transfer from the pi-donor guest to the NDI pi-acceptor units. We will investigate in this project the binding properties of NDI-PS gels towards different pi-donors such as naphthalene (D1), 1,5-dihidroxynaphthale (D2), 1,5-diaminonaphthalene (D3), 1,5-alkoxynaphthalene (D4).Also, the incorporation of donor guest (Dn) will be studied at different stage of the sol-gel process to understand their influence onto the structural organization of the 3D-network and on the mobility of the guest through the gel, since the binding force and the binding mode may alter the gelation mechanism, if the donors are placed together with the starting siloxane gelators, reflecting in the final gels. The photo- and electrochemical reduction of NDI-PS gels will be used as a strategy to eject/release the Dn species from D-A pairs. The redox properties of the NDI units will be exploited to develop stimulus-responsive gels. Finally, new class of polysilsesquioxane gel based on Viologens (V-PS) will be investigated and a similar approach to the NDI-PS gel will be carry out with V-PS gel. (AU)