Tunable iridium catalyst designs with bidentate N-heterocyclic carbene ligands for SABRE hyperpolarization of sterically hindered substrates.

Tunable iridium catalyst designs with bidentate N-heterocyclic carbene ligands for SABRE hyperpolarization of sterically hindered substrates.
Chem Commun (Camb). 2020 Nov 26;:
Authors: Pham P, Hilty C
Abstract
A series of bidentate N-heterocyclic carbene (NHC) iridium catalysts, [Ir(κC,N-NHC)H2L2]BPh4, are proposed for SABRE hyperpolarization. The steric and electronic properties of the NHCs are used to tune substrate affinity and thereby SABRE efficiency. The sterically hindered substrates 2,4-diaminopyrimidine and trimethoprim yielded maximum proton NMR signal enhancements of ∼300-fold and ∼150-fold, respectively.
PMID: 33241813 [PubMed - as supplied by publisher]

Source: Chemical Communications - November 26, 2020 Category: Chemistry Authors: Pham P, Hilty C Tags: Chem Commun (Camb) Source Type: research