DUAL ELECTROACTIVE PROBES OF CLAY FILM CHEMISTRY

In this paper we explore intermolecular effects on the transport of probe molecules in clays by pairing of electroactive probes. Among the interesting features of the dual-probe system, we note that analytically useful signals can be induced by ion pairing of an electroactive cation with an electroactive anion. Such electrochemically observable ion pairing was most successful when the anion was partially aromatic in nature. The results shed light on the role of organic coadsorbates in enhancing transport of small organics in clay beds. A second important observation is that, for some dual probes, diode behavior can be noted in which all the reduction current is observed at one redox couple and all the oxidative current is observed at the second redox couple.