{"database":"biostudies-literature","file_versions":[],"scores":null,"additional":{"submitter":["Hughes JWJ"],"funding":["University of Edinburgh","Horizon 2020 Framework Programme","Medical Research Council","Ramsay Memorial Fellowships Trust, University College London","Royal Society"],"pagination":["17767-17775"],"full_dataset_link":["https://www.ebi.ac.uk/biostudies/studies/S-EPMC10696559"],"repository":["biostudies-literature"],"omics_type":["Unknown"],"volume":["52(47)"],"pubmed_abstract":["Herein we report the synthesis, isolation and polymerisation activity of two new zinc compounds based on a 2,6-diisopropylphenyl (Dipp) β-diiminate (NacNac) ligand framework with zinc also ligated by an amidate (2-pyridonate or 6-methyl-2-pyridonate) unit. The compounds crystallised as either monomeric (6-Me-2-pyridonate derivative) or dimeric (2-pyridonate) species, although both were found to be monomeric in solution <i>via</i><sup>1</sup>H DOSY NMR spectroscopy, which was supported by DFT calculations. These observations suggest that both complexes initiate ring-opening polymerisation (ROP) through a single-site monometallic mechanism. High molecular weight poly ε-caprolactone (PCL) was achieved <i>via</i> exogenous initiator-free ROP conditions with both catalysts. An increase in the 2-pyridonate initiator steric bulk (6-Me- <i>vs.</i> 6-H-) resulted in an improved catalytic activity, facilitating complete monomer conversion within 1 h at 60 °C. Pyridonate end-groups were observed by MALDI-ToF mass spectrometry, contrasting with previous observations for <sup>Dipp</sup>NacNac-Zn acetate complexes (where no acetate end groups are observed), instead this more closely resembles the reactivity of <sup>Dipp</sup>NacNac-Zn alkoxide complexes in ROP (where RO end groups are observed). Additional major signals in the MALDI-ToF spectra were consistent with cyclic PCL species, which are attributed to back-biting ring-closing termination steps occuring in a process facilitated by the pyridonate unit being an effective leaving group. To the best of our knowledge, these complexes represent the first examples of pyridonate, and indeed amidate, initated ROP."],"journal":["Dalton transactions (Cambridge, England : 2003)"],"pubmed_title":["NacNac-zinc-pyridonate mediated ε-caprolactone ROP."],"pmcid":["PMC10696559"],"funding_grant_id":["769599","Future Leaders Fellowship MR\\T042710\\1","RSG\\R1\\180101"],"pubmed_authors":["Stowers-Veitch F","Babula DJ","Hughes JWJ","Ingleson MJ","Yuan K","Garden JA","Nichol GS","Uzelac M"],"additional_accession":[]},"is_claimable":false,"name":"NacNac-zinc-pyridonate mediated ε-caprolactone ROP.","description":"Herein we report the synthesis, isolation and polymerisation activity of two new zinc compounds based on a 2,6-diisopropylphenyl (Dipp) β-diiminate (NacNac) ligand framework with zinc also ligated by an amidate (2-pyridonate or 6-methyl-2-pyridonate) unit. The compounds crystallised as either monomeric (6-Me-2-pyridonate derivative) or dimeric (2-pyridonate) species, although both were found to be monomeric in solution <i>via</i><sup>1</sup>H DOSY NMR spectroscopy, which was supported by DFT calculations. These observations suggest that both complexes initiate ring-opening polymerisation (ROP) through a single-site monometallic mechanism. High molecular weight poly ε-caprolactone (PCL) was achieved <i>via</i> exogenous initiator-free ROP conditions with both catalysts. An increase in the 2-pyridonate initiator steric bulk (6-Me- <i>vs.</i> 6-H-) resulted in an improved catalytic activity, facilitating complete monomer conversion within 1 h at 60 °C. Pyridonate end-groups were observed by MALDI-ToF mass spectrometry, contrasting with previous observations for <sup>Dipp</sup>NacNac-Zn acetate complexes (where no acetate end groups are observed), instead this more closely resembles the reactivity of <sup>Dipp</sup>NacNac-Zn alkoxide complexes in ROP (where RO end groups are observed). Additional major signals in the MALDI-ToF spectra were consistent with cyclic PCL species, which are attributed to back-biting ring-closing termination steps occuring in a process facilitated by the pyridonate unit being an effective leaving group. To the best of our knowledge, these complexes represent the first examples of pyridonate, and indeed amidate, initated ROP.","dates":{"release":"2023-01-01T00:00:00Z","publication":"2023 Dec","modification":"2026-06-21T03:14:28.528Z","creation":"2025-04-05T22:24:31.309Z"},"accession":"S-EPMC10696559","cross_references":{"pubmed":["37981810"],"doi":["10.1039/d3dt03344a"]}}