Reaction of iodocarbonylbis(trimethylphosphine)rhodium(I) with parahydrogen leads to the observation of five characterisable H2 addition products

Parahydrogen-based NMR methods as a mechanistic probe in inorganic chemistry

“…Comparable results were obtained with the PMe 3 analogue, although in this case one of the hydride ligands was observed to bridge two rhodium centres [36]. Indeed, when the related complex RhI(CO)(PMe 3 ) 2 was reacted with parahydrogen, five different products were observed [37]. These species were characterized via PHIP enhanced methods and served to illustrate that complex reactions yielding previously unseen species can be detected using this approach.…”

Utilisation of water soluble iridium catalysts for signal amplification by reversible exchange

“…Ir I -complexes containing both N-heterocyclic carbene (NHC) and phosphine ligands have been found to show very good catalytic activity in the homogeneous hydrogenation of olefins. 1 In the case of [Ir(COD)(IMes)(P( n Bu) 3 )]PF 6 , where IMes is the N-heterocyclic carbene (NHC) 1,3-bis(2,4,6-trimethylphenyl)-imidazol-2-ylidene, this activity has been studied by para-Hydrogen Induced Polarization (PHIP) and hyperpolarised nuclear magnetic resonance (NMR) signals were seen in the ethyl proton resonances of the hydrogenation product ethylbenzene. 2 para-Hydrogen ( p-H 2 ) 3 studies have been used to follow many such hydrogenation reactions and a number of reaction intermediates have been detected.…”

“…2 para-Hydrogen ( p-H 2 ) 3 studies have been used to follow many such hydrogenation reactions and a number of reaction intermediates have been detected. [4][5][6][7][8] Traditionally, two different effects are seen when reactions with p-H 2 are examined. These correspond to para-Hydrogen and Synthesis Allow Dramatically Enhanced Nuclear Alignment (PASADENA) 4,5,7 when the reaction proceeds in high magnetic field, and Adiabatic Longitudinal Transport After Dissociation Engenders Net Alignment (ALTADENA 9 ) for reactions that occur in low magnetic field.…”

Contrasting Photochemical and Thermal Catalysis by Ruthenium Arsine Complexes Revealed by Parahydrogen Enhanced NMR Spectroscopy

“…In‐situ photolysis [47] has also been used to explore the evolution of NMR coherences that become accessible via p ‐H 2 addition to a metal complex [48,49] with a view to harnessing these approaches to study fast reactions [49,50] . Thermally activated PHIP approaches have yielded information on the catalytic role of a number of mono‐, [51,52] di‐ [53,54] and tri‐nuclear [55] transition metal species. Other achievements in this field include the sensitization of hydroformylation products [56] as well as demonstrations that key species in cobalt‐ and iridium‐catalysed hydroformylation processes can be detected [57] .…”