Modulation of the metal recognition properties of a new type of azaferrocenophane-based chemosensors: co-ordination chemistry towards Mg2+, Ca2+, Zn2+ and Ni2+.
The structure-redox chemistry relationship of a new type of azaferrocenophane-based chemosensors, 3 and 4, in the presence of protons and several kinds of metal ions, has been studied. Electrochemical studies, carried out in CH2Cl2, in the presence of increasing amounts of Mg2+, Ca2+, Zn2+ and Ni2+ showed that the wave corresponding to the Fc/Fc+ couple of the uncomplexed ligands is gradually replaced by a new reversible wave at more positive potentials corresponding to the Fc/Fc+ couple of the complexed ligands. The maximum shift of the ferrocene oxidation wave was found for 4b in the presence of Mg2+, whereas for 3f a selective sensing response for Mg2+ in the presence of hydrated Ca2+ cations was observed, with a concomitant highly visual output response consisting of a deep purple colour.
Tárraga
Alberto
A
Departamento de Quimica Organica, Facultad de Quimica, Universidad de Murcia, Campus de Espinardo, E-30100 Murcia, Spain.
Molina
Pedro
P
López
Juan L
JL
Velasco
María D
MD