SYNTHESIS AND CYCLIC VOLTAMMETRY STUDIES OF COPPER-COMPLEXES OF BROMOPHENYL-SUBSTITUTED AND ALKOXYPHENYL-SUBSTITUTED DERIVATIVES OF TRIS(2-PYRIDYLMETHYL)AMINE - INFLUENCE OF CATION-ALKOXY INTERACTIONS ON COPPER REDOX POTENTIALS

A combination of host-guest chemistry and coordination chemistry in th e design of electrochemical sensors for alkali metal and ammonium ions is described. The sensor molecules are coordination complexes between a copper ion and a functionalized tripodal ligand. Upon presentation of the ion to the sensor molecule, a shift in the redox potential of t he copper ion occurs. In the course of the study, three new alkoxyphen yl-substituted derivatives of the ligand tris(2-pyridylmethyl)amine (T PA) were prepared and characterized. The synthesis of the new ligands involved the preparation of bromopyridyl-TPA derivatives followed by S uzuki coupling with substituted phenylboronic acids. Cyclic voltammetr y studies of copper complexes of the ligands indicated that steric eff ects played a dominant role in the overall determination of the copper redox couple. Studies of the alkoxyphenyl ligands indicated that smal l but reproducible changes in the copper redox couple occurred upon pr esentation of a guest cation that would be expected to form a complex with the copper-ligand complex.