165221 20260418110659.0 doi 10.1021/acs.inorgchem.5c03962 sideral 146754 ART-2025-146754 eng García-Abellán, Susana Hemilability Modulation via Phosphane-Triazole Ligand Design: Impact on Catalytic Formic Acid Dehydrogenation 2025 Access copy available to the general public Unrestricted Two novel P–N ligands, 1-[2-(diphenylphosphanyl)ethyl]-1H-benzo-1,2,3-triazole (1) and its N2-isomer (2), were synthesized. Reaction of 1 and 2 with [Ir(μ-Cl)(cod)]2 and [Rh(μ-Cl)(cod)]2 in a 2:1 molar ratio followed by AgBF4 led to the formation of square-planar κ2-P,N complexes, Ir-1, Ir-2, Rh-1 and Rh-2. Density functional theory studies provided insights into the electronic structure and bonding of the complexes. Complex Ir-3 was also prepared for comparison, employing ligand 3, 1-[2-(diphenylphosphanyl)methyl]-1H-benzo-1,2,3-triazole. Variable-temperature NMR studies on [IrCl(cod)(P–N)] complexes revealed fluxional behavior attributed to ligand hemilability. Activation Gibbs free energies (ΔG‡) for the isomerization equilibrium of [IrCl(cod)(PN)] complexes featuring ligands 1, 2 and 3 are 10.24, 10.60, and 8.87 kcal·mol–1, respectively. This enabled us to propose a coordination-ability scale that follows the trend 3 > 1 > 2. The relative activities of the iridium complexes were evaluated in the dehydrogenation of formic acid. Under optimized conditions, in an HCOOH/Et3N mixture, the initial TOFs are 186, 828, and 948 h–1 for Ir-1, Ir-2, and Ir-3, respectively. This indicates that Ir-3, bearing the most strongly coordinating ligand, exhibits the highest catalytic activity, reaching a TON value of 444 after 7 h. This study demonstrates the tunability of the hemilability of benzo-1,2,3-triazole-based P–N ligands and their potential for modulating catalytic activity. info:eu-repo/grantAgreement/ES/DGA/E42-23R info:eu-repo/grantAgreement/ES/MICINN/PID2021-122763NB-I00 info:eu-repo/grantAgreement/ES/MICINN/PID2021-126212OB-I00 info:eu-repo/semantics/openAccess by https://creativecommons.org/licenses/by/4.0/deed.es info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Pérez-García, Andrea Universidad de Zaragoza Barrena-Espés, Daniel Casado, Miguel A. Universidad de Zaragoza (orcid)0000-0003-1707-3022 Munarriz, Julen Universidad de Zaragoza (orcid)0000-0001-6089-6126 Passarelli, Vincenzo (orcid)0000-0002-1735-6439 Iglesias, Manuel (orcid)0000-0003-3144-5320 2010 760 Universidad de Zaragoza Dpto. Química Inorgánica Área Química Inorgánica 2012 755 Universidad de Zaragoza Dpto. Química Física Área Química Física 64, 50 (2025), 24539-24552 Inorg. chem. Inorganic Chemistry 0020-1669 4525666 http://zaguan.unizar.es/record/165221/files/texto_completo.pdf Versión publicada 2938218 http://zaguan.unizar.es/record/165221/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:165221 articulos driver 2026-04-18-11:05:08 ARTICLE