Coordination chemistry of novel multifunctional pyridylphosphine ligands.
Abstract
Coordination complexes with ligands that incorporate multiple donor moieties have been of particular interest due to the unique and diverse characteristics they can possess. In particular, phosphine- and/or nitrogen-based ligands that are designed to be geometrically flexible have been shown to demonstrate coordination modes that favor the formation of complexes that range from small discrete molecules to extended polymeric networks. The purposeful design of these architectures is often complicated by the unpredictable influence of factors such as crystallization solvent, interaction of counterion, metal-to-ligand reaction ratio, and presence of auxiliary ligands. However, these same factors aid in the isolation of novel metal complexes and lend a better understanding of the nature of the ligand. In this work, a new family of pyridylphosphine ligands are featured with various metal salts and select bipyridine derivatives. The coordination complexes range from smaller discrete molecules to 1-dimensional polymers depending heavily on the preference of the ligand: the ability or inability to chelate. Ligands that do not have the ability to chelate are limited to bridging as a sole mode of coordination and often result in the formation of polymers, while ligands that are capable of chelation often result in the formation of simple to complex discrete molecules. In addition to single crystal X-ray crystallography, all complexes were characterized via ¹H and ³¹P NMR spectroscopy, elemental analysis, as well as photoluminescence spectroscopy when applicable.