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abstracts
N,N'-Disubstituted hydroxyamidines/ α-aminonitrones (AMOXs) present high steric and electronic modularity (substituents can be varied on the central C atom and/or on the N atoms) resulting in precise electronic tunability, enhanced by the delocalization on the amidine backbone. They are good chelating ligands, forming stable 5-membered chelate rings with metal ions, and they also present hydrogen bonding capacity. [1] In our research, we exploit these properties by investigating their incorporation into supramolecular assemblies based on coordination chemistry and/ or hydrogen bonding. Herein, we present the synthesis and the structural characterization of different mono- and bis-AMOX type compounds. [2] The analysis of the hydrogen bonding patterns found in each case is highlighted (Figure 1), in an effort to identify factors (e.g. substituent effects: sterics and/ or electronics, other type of supramolecular interactions) that are generating specific hydrogen-bonding patterns. Understanding and rationalizing such a cause – effect relationship is of paramount importance in order to efficiently use hydrogen bonding as a crystal engineering design tool. Figure 1. Type of hydrogen bonding pattern in AMOX type compounds. [3]
abstracts
Our main building blocks for forming supra-molecular assemblies of chromophoric units are the rhodium amidinate dimers. They offer an excellent structural backbone for rigid polynuclear assemblies with their paddle wheel motif and strongly bonded ligands. We already showed that with a well designed amidinate ligand with a pyridyl group up to four metallic centers can be attached to the dimer.[1,2] Two main approaches were used to extend these assemblies: the first is through Suzuki coupling reactions which allows for an extended ligand and a control on the number of pyridyl present on the dimer; The second is through bisisocyanide ligands which are used to bridge the dimers though their axial site, thus forming 1D coordination polymer in the solid state. These different assemblies will be presented with their solid state structure, photophysical and electrochemical properties.
