Eastwood, Jonathan, Hammarback, Anders, McRobie, Matthew et al. (4 more authors) (2020) Time-resolved infra-red spectroscopy reveals competitive water and dinitrogen coordination to a manganese(I) carbonyl complex. Dalton Transactions. ISSN 1477-9234
Abstract
Time-resolved infra-red (TRIR) spectroscopy has been used to demonstrate that photolysis of [Mn(C^N)(CO)4] (C^N = bis-(4-methoxyphenyl)methanimine) in heptane solution results in ultra-fast CO dissociation and ultimate formation of a rare Mn-containing dinitrogen complex fac-[Mn(C^N)(CO)3(N2)] with a diagnostic stretching mode for a terminal-bound N[triple bond, length as m-dash]N ligand at 2249 cm−1. An isotopic shift to 2174 cm−1 was observed when the reaction was performed under 15N2 and the band was not present when the experiment was undertaken under an atmosphere of argon, reinforcing this assignment. An intermediate solvent complex fac-[Mn(C^N)(CO)3(heptane)] was identified which is formed in less than 2 ps, indicating that CO-release occurs on an ultra-fast timescale. The heptane ligand is labile and is readily displaced by both N2 and water to give fac-[Mn(C^N)(CO)3(N2)] and fac-[Mn(C^N)(CO)3(OH2)] respectively. The fac-[Mn(C^N)(CO)3(heptane)] framework showed a significant affinity for N2, as performing the reaction under air produced significant amounts of fac-[Mn(C^N)(CO)3(N2)]. Kinetic analysis reveals that the substitution of heptane by N2 (k = (1.028 ± 0.004) × 109 mol−1 dm3 s−1), and H2O is competitive on fast (<1 μs) time scales. The binding of water is reversible and, under an atmosphere of N2, some fac-[Mn(C^N)(CO)3(OH2)] converts to fac-[Mn(C^N)(CO)3(N2)].
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © The Royal Society of Chemistry 2020. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details. |
Dates: |
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Institution: | The University of York |
Academic Units: | The University of York > Faculty of Sciences (York) > Chemistry (York) |
Depositing User: | Pure (York) |
Date Deposited: | 28 Apr 2020 14:10 |
Last Modified: | 30 Dec 2024 00:12 |
Published Version: | https://doi.org/10.1039/C9DT04878B |
Status: | Published online |
Refereed: | Yes |
Identification Number: | 10.1039/C9DT04878B |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:159970 |
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