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A novel Pt(iv) mono azido mono triazolato complex evolves azidyl radicals following irradiation with visible light

The platinum(iv) azido complex trans,trans,trans-[Pt(IV)(N(3))(2)(OH)(2)(py)(2)] (1) undergoes cycloaddition with 1,4-diphenyl-2-butyne-1,4-dione (2) under mild, catalyst-free conditions, affording a number of mono and bis click products. The major mono click product (3) exists in MeCN as an equilib...

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Autores principales: Yao, Kezi, Bertran, Arnau, Morgan, Jacques, Hare, Samuel M., Rees, Nicholas H., Kenwright, Alan M., Edkins, Katharina, Bowen, Alice M., Farrer, Nicola J.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Royal Society of Chemistry 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6984332/
https://www.ncbi.nlm.nih.gov/pubmed/31012460
http://dx.doi.org/10.1039/c9dt01156k
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author Yao, Kezi
Bertran, Arnau
Morgan, Jacques
Hare, Samuel M.
Rees, Nicholas H.
Kenwright, Alan M.
Edkins, Katharina
Bowen, Alice M.
Farrer, Nicola J.
author_facet Yao, Kezi
Bertran, Arnau
Morgan, Jacques
Hare, Samuel M.
Rees, Nicholas H.
Kenwright, Alan M.
Edkins, Katharina
Bowen, Alice M.
Farrer, Nicola J.
author_sort Yao, Kezi
collection PubMed
description The platinum(iv) azido complex trans,trans,trans-[Pt(IV)(N(3))(2)(OH)(2)(py)(2)] (1) undergoes cycloaddition with 1,4-diphenyl-2-butyne-1,4-dione (2) under mild, catalyst-free conditions, affording a number of mono and bis click products. The major mono click product (3) exists in MeCN as an equilibrium mixture between two species; 3a and 3b rapidly interconvert through nucleophilic attack of the axial Pt–OH group at the adjacent Ph–CO group. The kinetic and thermodynamic parameters for this interconversion have been measured by selective saturation-transfer NMR spectroscopic experiments and are consistent with cyclisation at the Pt centre. Complex 3b was also characterised by X-ray crystallography. Visible light irradiation (440–480 nm) of 3 in d(3)-MeCN produces azidyl radicals (N(3)˙), as demonstrated by EPR spin-trapping with DMPO; no generation of hydroxyl radicals was observed. (1)H–(195)Pt HMBC NMR confirmed that the photoproducts were Pt(IV) rather than Pt(II) species, and HPLC was consistent with these being [3–N(3)](+) species; no facile photoejection of the triazolato ligand was observed, consistent with MS/MS fragmentation of 3. When 3 was irradiated in the presence of 5′-GMP, no 5′-GMP photoproducts were observed, suggesting that complex 3 is likely to exhibit significantly simplified biological activity (release of azidyl radicals but not DNA binding) compared with complex 1.
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spelling pubmed-69843322020-03-04 A novel Pt(iv) mono azido mono triazolato complex evolves azidyl radicals following irradiation with visible light Yao, Kezi Bertran, Arnau Morgan, Jacques Hare, Samuel M. Rees, Nicholas H. Kenwright, Alan M. Edkins, Katharina Bowen, Alice M. Farrer, Nicola J. Dalton Trans Chemistry The platinum(iv) azido complex trans,trans,trans-[Pt(IV)(N(3))(2)(OH)(2)(py)(2)] (1) undergoes cycloaddition with 1,4-diphenyl-2-butyne-1,4-dione (2) under mild, catalyst-free conditions, affording a number of mono and bis click products. The major mono click product (3) exists in MeCN as an equilibrium mixture between two species; 3a and 3b rapidly interconvert through nucleophilic attack of the axial Pt–OH group at the adjacent Ph–CO group. The kinetic and thermodynamic parameters for this interconversion have been measured by selective saturation-transfer NMR spectroscopic experiments and are consistent with cyclisation at the Pt centre. Complex 3b was also characterised by X-ray crystallography. Visible light irradiation (440–480 nm) of 3 in d(3)-MeCN produces azidyl radicals (N(3)˙), as demonstrated by EPR spin-trapping with DMPO; no generation of hydroxyl radicals was observed. (1)H–(195)Pt HMBC NMR confirmed that the photoproducts were Pt(IV) rather than Pt(II) species, and HPLC was consistent with these being [3–N(3)](+) species; no facile photoejection of the triazolato ligand was observed, consistent with MS/MS fragmentation of 3. When 3 was irradiated in the presence of 5′-GMP, no 5′-GMP photoproducts were observed, suggesting that complex 3 is likely to exhibit significantly simplified biological activity (release of azidyl radicals but not DNA binding) compared with complex 1. Royal Society of Chemistry 2019-05-21 2019-04-23 /pmc/articles/PMC6984332/ /pubmed/31012460 http://dx.doi.org/10.1039/c9dt01156k Text en This journal is © The Royal Society of Chemistry 2019 https://creativecommons.org/licenses/by/3.0/This article is freely available. This article is licensed under a Creative Commons Attribution 3.0 Unported Licence (CC BY 3.0)
spellingShingle Chemistry
Yao, Kezi
Bertran, Arnau
Morgan, Jacques
Hare, Samuel M.
Rees, Nicholas H.
Kenwright, Alan M.
Edkins, Katharina
Bowen, Alice M.
Farrer, Nicola J.
A novel Pt(iv) mono azido mono triazolato complex evolves azidyl radicals following irradiation with visible light
title A novel Pt(iv) mono azido mono triazolato complex evolves azidyl radicals following irradiation with visible light
title_full A novel Pt(iv) mono azido mono triazolato complex evolves azidyl radicals following irradiation with visible light
title_fullStr A novel Pt(iv) mono azido mono triazolato complex evolves azidyl radicals following irradiation with visible light
title_full_unstemmed A novel Pt(iv) mono azido mono triazolato complex evolves azidyl radicals following irradiation with visible light
title_short A novel Pt(iv) mono azido mono triazolato complex evolves azidyl radicals following irradiation with visible light
title_sort novel pt(iv) mono azido mono triazolato complex evolves azidyl radicals following irradiation with visible light
topic Chemistry
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6984332/
https://www.ncbi.nlm.nih.gov/pubmed/31012460
http://dx.doi.org/10.1039/c9dt01156k
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