Related Experiment Video
Updated: Feb 23, 2026
IridiumIII Luminescent Probe for Detection of the Malarial Protein Biomarker Histidine Rich Protein-II
Published on: July 7, 2015
Detection of an Iridium-Dihydrogen Complex: A Proposed Intermediate in Ionic Hydrogenation
Jonathan M Goldberg1, Karen I Goldberg1, D Michael Heinekey1
1Department of Chemistry, University of Washington , Seattle, Washington 98195-1700, United States.
Abstract:
Addition of high pressures of H2 to five-coordinate [(tBu)4(POCOP)Ir(CO)(H)]OTf [(tBu)4(POCOP) = κ3-C6H3-2,6-(OP(tBu)2)2] complexes results in observation of two new iridium-dihydrogen complexes. If the aryl moiety of the POCOP ligand is substituted with an electron withdrawing protonated dimethylamino group at the para position, hydrogen coordination is enhanced. Five-coordinate Ir-H complexes generated by addition of triflic acid to (tBu)4(POCOP)Ir(CO) species show an Ir-H 1H NMR chemical shift dependence on the number of equivalents of acid present. It is proposed that excess triflic acid in solution facilitates triflate dissociation from iridium, resulting in unsaturated five-coordinate Ir-H complexes. The five-coordinate iridium-hydride complexes were found to catalyze H/D exchange between H2 and CD3OD. The existence of the dihydrogen complexes, as well as isotope exchange reactions, provide evidence for proposed ionic hydrogenation intermediates for glycerol deoxygenation.
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