Oxamato-based dicopper(II) metallacyclophanes as prototypes of magnetic devices for molecular spintronicsA joint experimental and computational study

Résumé

The work presented in this thesis constitutes a successful extension of our group’s research on the chemistry of dinuclear copper(II) metallacyclic complexes with dinucleating aromatic dioxamato ligands containing potential redox- and photoactive, extended ?-conjugated aromatic spacers. Using simple dicopper(II) metallacyclophanes as dynamic multifunctional magnetic systems to perform specific and selective tasks under the control of an external stimulus that switches “ON” and “OFF” their electronic (optical, redox, and/or magnetic) properties may have an enormous impact in several domains of molecular nanosciences. In doing so, we have followed a joint experimental and theoretical approach based on ligand design that profits from the use of several physical (spectroscopic, magnetic, electrochemical, and/or photochemical) and computational (DF and TDDF) techniques. The novel class of oxamato-based dicopper(II) metallacyclophanes developed in this thesis provides excellent synthetic and theoretical models for the fundamental study on long distance electron exchange and electron- or photo-triggered electron exchange phenomena, which are two central topics in the related fields of molecular magnetism and molecular spintronics. Indeed, these simple molecules appear as very promising candidates to get multifunctional magnetic devices facilitating the spin communication ('molecular magnetic wires', MMWs) or exhibiting spin charge storage ('molecular magnetic capacitors', MMCs) and bistable spin behavior ('molecular magnetic switches', MMSs) for potential applications in information processing and storage. This work is placed at the intercrossing area of several molecular and supramolecular disciplines including coordination chemistry, spectro- and magnetochemistry, and electro- and photochemistry. The design and synthesis of metallacyclic molecules that contain multiple electro- and photoactive, either metal- or ligand-based, spin carriers and the study of their spectroscopic and magnetic properties as well as their redox and photochemical activity are of large interest in the multidisciplinary field of molecular magnetism. The variety of single-molecule magnetic behaviors reported in each chapter of this thesis illustrates the potential of electro- and photoactive, oxamato-based dicopper(II) metallacyclophanes as prototypes of molecular magnetic devices in the emerging field of molecular spintronics.