Redox Activity of Copper(II) Complexes with NSFRY Pentapeptide and Its Analogues.

The influence of cation-π interactions on the electrochemical properties of copper(II) complexes with synthesized pentapeptide C-terminal fragment of Atrial Natriuretic Factor (ANF) hormone was studied in this work. Molecular modeling performed for Cu(II)-NSFRY-NH2 complex indicated that the cation-π interactions between Tyr and Cu(II), and also between Phe-Arg led to specific conformation defined as peptide box, in which the metal cation is isolated from the solvent by peptide ligand. Voltammetry experiments enabled to compare the redox properties and stability of copper(II) complexes with NSFRY-NH2 and its analogues (namely: NSFRA-NH2, NSFRF-NH2, NSAAY-NH2, NSAAA-NH2, AAAAA-NH2) as well as to evaluate the contribution of individual amino acid residues to these properties.

Interactions of dithiolated tetraazamacrocyclic copper(II) and nickel(II) complexes self-assembled on gold electrodes with pi-electron deficient molecules in solution.

Self-assembled monolayers of dithiolated neutral monotetraazamacrocyclic complexes of copper(II) and nickel(II) can provide molecularly defined platforms for the formation of a pseudorotaxane-like nanostructures on the gold electrode surface. We propose these complexes as pi-donor building blocks for the construction of new molecular devices. We show that these perpendicularly oriented macrocyclic complexes anchored to the electrode surface act as pi-electron rich species interacting with pi-electron deficient compounds dissolved in solution, such as fluorine derivatives of tetracyanoquinodimethane (F(4)TCNQ) or a charged bismacrocyclic tetraaza complex of copper(II).