DUAL ELECTROACTIVE PROBES OF CLAY FILM CHEMISTRY

In this paper we explore intermolecular effects on the transport of pr obe molecules in clays by pairing of electroactive probes. Among the i nteresting features of the dual-probe system, we note that analyticall y useful signals can be induced by ion pairing of an electroactive cat ion 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 note d in which all the reduction current is observed at one redox couple a nd all the oxidative current is observed at the second redox couple.