Electrochemical and pH control of the complexation/decomplexation of 4-amino-N,N-diphenylamine with beta-cyclodextrin

The behavior of the inclusion complex based on 4-amino-N,N-diphenylamine (A DPA) and cyclodextrin was studied by several techniques at different pH val ues and in different oxidation states. The results indicate that the revers ible inclusion of the guest compound depends on its protonation state, and that its oxidation and reduction occur outside the cyclodextrin cavity. Mor eover, the product of the guest bielectronic oxidation reaction is protonat ed and is free mainly, but in the presence of cyclodextrin and at neutral p H, it fits back into the cavity. This work shows that it is possible to con trol, by the pH and/or the applied potential, the complexation of ADPA or i ts oxidation product in a cyclodextrin cavity and gives information for syn thesizing encapsulated conductive polymers based on a PANI like structure. (C) 2000 Elsevier Science S.A. All rights reserved.