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Photoinduced and ground state conversions in a cyclic β-thioxoketone.

ABSTRACT: The photochemistry of a cyclic β-thioxoketone (2-methyl-1-(2-thioxycyclohexyl)propan-1-one (MTPO)) is investigated by NMR, UV, and IR experiments supported by DFT calculations. MTPO exists as a tautomeric mixture of an enol and a thiol form. Irradiation at low temperature led to a cis-trans isomerization of the thiol form resulting in a rather unusual enethiol (3). This is followed by a transfer of the isopropyl methine proton onto the carbonyl carbon resulting in yet another enethiol isomer (4). The photoconversion mechanisms without water present are discussed. Photochemical experiments at ambient temperature showed involvement of water in the excited state and resulted in another keto-form (5). The same species was also obtained when the products of the low temperature experiments were kept in the dark at ambient temperature.

SUBMITTER: Pietrzak M

PROVIDER: S-EPMC8697321 | biostudies-literature | 2021 Dec

REPOSITORIES: biostudies-literature

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Photoinduced and ground state conversions in a cyclic β-thioxoketone.

Pietrzak Mariusz M Buczyńska Joanna J Duus Fritz F Waluk Jacek J Hansen Poul Erik PE

RSC advances 20211223 2

The photochemistry of a cyclic β-thioxoketone (2-methyl-1-(2-thioxycyclohexyl)propan-1-one (MTPO)) is investigated by NMR, UV, and IR experiments supported by DFT calculations. MTPO exists as a tautomeric mixture of an enol and a thiol form. Irradiation at low temperature led to a <i>cis</i>-<i>trans</i> isomerization of the thiol form resulting in a rather unusual enethiol (3). This is followed by a transfer of the isopropyl methine proton onto the carbonyl carbon resulting in yet another eneth ...[more]

PMID: 35425142

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