Abstract
A chelating ligand formed by deprotonation of 2-(2′-pyridyl)-2-propanol stabilizes a distorted trigonal bipyramidal geometry in a 16e- d6 5-coordinate iridium complex with the alkoxide acting as a π donor. Ambiphilic species such as AcOH bearing both nucleophilic and electrophilic functionality form adducts with the unsaturated iridium complex which contain strong intramolecular O***H***O hydrogen bonds that involve the basic alkoxide oxygen. Density functional theory (DFT) calculations on the isolated cations reproduce with high accuracy the geometrical features obtained via X-ray diffraction and corroborate the presence of very short hydrogen bonds with O***O distances of about 2.4 Å. Calculations further confirm the known trend that the hydrogen position in these bonds is sensitive to the O***O distance, with the shortest distances giving rise to symmetrical O***H***O interactions. Dihydrogen is shown to add across the Ir-O π bond in a presumed proton transfer reaction, demonstrating bifunctional behavior by the iridium alkoxide.