abstract
Poly[Cu(3-MeOsalpd)] films with good physical, chemical and electrochemical stability may be potentiodynamically electrodeposited with high deposition efficiency from acetonitrile solutions of the monomer. Comparative coulometric assays with the Ni-based analogue show that the metal in the salen motif does play a role in the electronic structure of the polymer, but that the electroactive response is ligand (not metal) based. The dynamics of redox switching are ultimately limited by coupled electron/counter ion diffusion, but this process is sufficiently rapid that it influences the voltammetric response only for thick films (I" > 420 nmol cm(-2)) at high scan rates. Redox cycling in monomer-free electrolyte shows a voltammetric signature that responds, via interaction with the pseudo-crown ether receptor sites, to the presence of Li+, K+, Mg2+ and Ba2+ ions in solution. The most prominent change is associated with the first anodic peak in the i-E signature. For each of the metal ions considered, this peak potential responds logarithmically to concentration in a manner that varies with individual complexed cation and film thickness and to an extent greater than predicted by the Nernst equation. The film characteristics offer some analytical promise, including a trade-off between sensitivity and dynamic range and signal amplification, possibly due to supramolecular effects.
keywords
POLYMER-FILMS; CROWN-ETHER; MODIFIED ELECTRODES; SPECTROELECTROCHEMICAL CHARACTERIZATION; ELECTROCHEMICAL PROPERTIES; MOLECULAR RECOGNITION; POLYTHIOPHENES; SALEN; COORDINATION; SENSORS
subject category
Electrochemistry
authors
Kiersztyn, I; Neto, L; Carneiro, A; Tedim, J; Freire, C; Hillman, AR
our authors
João Tedim
Associate Professoracknowledgements
This work was partially funded by Fundacao para a Ciencia e a Tecnologia (FCT), Portugal, through Proj. Ref. PTDC/QUI/67786/2006 and through grant no. PEst-C/EQB/LA0006/2011. IK, AC and JT thank Fundacao para a Ciencia e a Tecnologia for grants.