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-[PtIV(N3)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 mixtu...
| Main Authors: | , , , , , , , , |
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| Format: | Journal article |
| Language: | English |
| Published: |
Royal Society of Chemistry
2019
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| _version_ | 1797087213711785984 |
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| author | Yao, K Bertran, A Morgan, J Hare, S Rees, N Kenwright, A Edkins, K Bowen, A Farrer, N |
| author_facet | Yao, K Bertran, A Morgan, J Hare, S Rees, N Kenwright, A Edkins, K Bowen, A Farrer, N |
| author_sort | Yao, K |
| collection | OXFORD |
| description | The platinum(iv) azido complex trans,trans,trans-[PtIV(N3)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 d3-MeCN produces azidyl radicals (N3˙), as demonstrated by EPR spin-trapping with DMPO; no generation of hydroxyl radicals was observed. 1H-195Pt HMBC NMR confirmed that the photoproducts were PtIV rather than PtII species, and HPLC was consistent with these being [3-N3]+ 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. |
| first_indexed | 2024-03-07T02:32:36Z |
| format | Journal article |
| id | oxford-uuid:a7c002c0-14ee-4b73-854c-1b819a1f3d48 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T02:32:36Z |
| publishDate | 2019 |
| publisher | Royal Society of Chemistry |
| record_format | dspace |
| spelling | oxford-uuid:a7c002c0-14ee-4b73-854c-1b819a1f3d482022-03-27T02:56:39ZA novel Pt(iv) mono azido mono triazolato complex evolves azidyl radicals following irradiation with visible lightJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:a7c002c0-14ee-4b73-854c-1b819a1f3d48EnglishSymplectic Elements at OxfordRoyal Society of Chemistry2019Yao, KBertran, AMorgan, JHare, SRees, NKenwright, AEdkins, KBowen, AFarrer, NThe platinum(iv) azido complex trans,trans,trans-[PtIV(N3)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 d3-MeCN produces azidyl radicals (N3˙), as demonstrated by EPR spin-trapping with DMPO; no generation of hydroxyl radicals was observed. 1H-195Pt HMBC NMR confirmed that the photoproducts were PtIV rather than PtII species, and HPLC was consistent with these being [3-N3]+ 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. |
| spellingShingle | Yao, K Bertran, A Morgan, J Hare, S Rees, N Kenwright, A Edkins, K Bowen, A Farrer, N 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 |
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