Analysis of chemical exchange in iridium N-heterocyclic carbene complexes using heteronuclear parahydrogen-enhanced NMR.

ABSTRACT: The signal amplification by reversible exchange process (SABRE) enhances NMR signals by unlocking hidden polarization in parahydrogen through interactions with to-be-hyperpolarized substrate molecules when both are transiently bound to an Ir-based organometallic catalyst. Recent efforts focus on optimizing polarization transfer from parahydrogen-derived hydride ligands to the substrate in SABRE. However, this requires quantitative information on ligand exchange rates, which common NMR techniques struggle to provide. Here, we introduce an experimental spin order transfer sequence, with readout occurring at ¹⁵N nuclei directly interacting with the catalyst. Enhanced ¹⁵N NMR signals overcome sensitivity challenges, encoding substrate dissociation rates. This methodology

SUBMITTER: Assaf CD 

PROVIDER: S-EPMC11614900 | biostudies-literature | 2024 Dec

REPOSITORIES: biostudies-literature