title: Utilisation of water soluble iridium catalysts for signal amplification by reversible exchange.
abstract: The catalytic hyperpolarisation of pyridine, 3-hydroxypyridine and oxazole by the Signal Amplification By Reversible Exchange (SABRE) process is achieved by a series of water soluble iridium phosphine and N-heterocyclic carbene dihydride complexes. While the efficiency of the SABRE process in methanol-d4 solution or ethanol-d6 solution is high, with over 400-fold (1)H polarisation of pyridine being produced by [Ir(H)2(NCMe)(py)(IMes)(monosulfonated-triphenylphosphine)]BF4, changing to a D2O or a D2O-ethanol solvent mixture leads to dramatically reduced activity which is rationalised in terms of low H2 solubility.
authors.affiliation: Centre for Hyperpolarization in Magnetic Resonance, University of York, York Science Park, York, YO10 5NY, UK. simon.duckett@york.ac.uk.
authors.forename: M
authors.initials: M
authors.lastname: Fekete
authors.forename: C
authors.initials: C
authors.lastname: Gibard
authors.forename: G J
authors.initials: GJ
authors.lastname: Dear
authors.forename: G G R
authors.initials: GG
authors.lastname: Green
authors.forename: A J J
authors.initials: AJ
authors.lastname: Hooper
authors.forename: A D
authors.initials: AD
authors.lastname: Roberts
authors.forename: F
authors.initials: F
authors.lastname: Cisnetti
authors.forename: S B
authors.initials: SB
authors.lastname: Duckett