Appleby, Kate M., Mewis, Ryan E., Olaru, Alexandra M. orcid.org/0000-0002-2244-1048 et al. (3 more authors) (2015) Investigating pyridazine and phthalazine exchange in a series of iridium complexes in order to define their role in the catalytic transfer of magnetisation from para-hydrogen. Chemical Science. pp. 3981-3993. ISSN 2041-6539
Abstract
The reaction of [Ir(IMes)(COD)Cl], [IMes = 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene, COD = 1,5-cyclooctadiene] with pyridazine (pdz) and phthalazine (phth) results in the formation of [Ir(COD)(IMes)(pdz)]Cl and [Ir(COD)(IMes)(phth)]Cl. These two complexes are shown by nuclear magnetic resonance (NMR) studies to undergo a haptotropic shift which interchanges pairs of protons within the bound ligands. When these complexes are exposed to hydrogen, they react to form [Ir(H)<inf>2</inf>(COD)(IMes)(pdz)]Cl and [Ir(H)<inf>2</inf>(COD)(IMes)(phth)]Cl, respectively, which ultimately convert to [Ir(H)<inf>2</inf>(IMes)(pdz)<inf>3</inf>]Cl and [Ir(H)<inf>2</inf>(IMes)(phth)<inf>3</inf>]Cl, as the COD is hydrogenated to form cyclooctane. These two dihydride complexes are shown, by NMR, to undergo both full N-heterocycle dissociation and a haptotropic shift, the rates of which are affected by both steric interactions and free ligand pK<inf>a</inf> values. The use of these complexes as catalysts in the transfer of polarisation from para-hydrogen to pyridazine and phthalazine via signal amplification by reversible exchange (SABRE) is explored. The possible future use of drugs which contain pyridazine and phthalazine motifs as in vivo or clinical magnetic resonance imaging probes is demonstrated; a range of NMR and phantom-based MRI measurements are reported.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © The Royal Society of Chemistry 2015. This content is made available by the publisher under a Creative Commons CC-BY-NC Licence |
Dates: |
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Institution: | The University of York |
Academic Units: | The University of York The University of York > Faculty of Sciences (York) > Chemistry (York) The University of York > Faculty of Sciences (York) > Psychology (York) |
Depositing User: | Pure (York) |
Date Deposited: | 06 Oct 2015 11:53 |
Last Modified: | 07 Feb 2025 00:11 |
Published Version: | https://doi.org/10.1039/c5sc00756a |
Status: | Published |
Refereed: | Yes |
Identification Number: | 10.1039/c5sc00756a |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:90519 |