High-Yielding Synthesis of Cyclometallated Iridium Complexes with Hydrogen Bond-Rich Ligands

A library of cyclometallated iridium (III) complexes with a strong H-bonding motif in their ancillary ligand was synthesized, characterized and their photophysical properties measured. Demonstrated herein is a general synthetic high yield procedure for these compounds. We ascribe these yields to the use of an intermediary primer ligand. This de novo strategy circumnavigates the standard synthetic issues of H-bond rich ligand precursors (self-aggregation and poor solubility in organic solvents). Alternative and greener synthetic pathways were also explored to realize the intermediate iridium primer complex.