Synthesis and electrochemical polymerization of calix[4]arenes containing N-substituted pyrrole moieties

Attaching a redox active moiety, such as ferrocene or quinone, in close proximity to the receptor site of a macrocyclic molecule has been shown to be an efficient way to couple complexation and redox reactions [1,2]. These coupled systems have been utilized to recognize or sense electrochemically various guest species [3-5]. They have the ability to control the stability of a complex formed between the receptor and a charged guest species through the oxidation or reduction of the redox centre via electrochemical means [6,7]. While these successes have been achieved for redox-active macrocyclic molecules in solution, it is a challenge to repeat these results for such molecules immobilized on an electrode surface, which will allow better control and wider applications in the field of chemical sensor technology. For instance, chemically bonding redox-active macrocyclic molecules onto an inert electrode surface or incorporating them into a conducting polymer matrix can provide great convenience in fabricating an electrochemical sensor [8].In this article we have appended redox-active pyrrole moieties to a calix[4]arene in an effort to produce a novel polypyrrole-calix[4]arene modified electrode via electropolymerization techniques