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Tuning phenoxyl-substituted diketopyrrolopyrroles from quinoidal to biradical ground states through (hetero-)aromatic linkers
Strongly fluorescent halochromic 2,6-di-tert-butyl-phenol-functionalised phenyl-, thienyl- and furyl-substituted diketopyrrolopyrrole (DPP) dyes were deprotonated and oxidised to give either phenylene-linked DPP1˙˙ biradical (y(0) = 0.75) with a singlet open shell ground state and a thermally popula...
Autores principales: | , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
The Royal Society of Chemistry
2020
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8179021/ https://www.ncbi.nlm.nih.gov/pubmed/34163813 http://dx.doi.org/10.1039/d0sc05475e |
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author | Rausch, Rodger Röhr, Merle I. S. Schmidt, David Krummenacher, Ivo Braunschweig, Holger Würthner, Frank |
author_facet | Rausch, Rodger Röhr, Merle I. S. Schmidt, David Krummenacher, Ivo Braunschweig, Holger Würthner, Frank |
author_sort | Rausch, Rodger |
collection | PubMed |
description | Strongly fluorescent halochromic 2,6-di-tert-butyl-phenol-functionalised phenyl-, thienyl- and furyl-substituted diketopyrrolopyrrole (DPP) dyes were deprotonated and oxidised to give either phenylene-linked DPP1˙˙ biradical (y(0) = 0.75) with a singlet open shell ground state and a thermally populated triplet state (ΔE(ST) = 19 meV; 1.8 kJ mol(−1); 0.43 kcal mol(−1)) or thienylene/furylene-linked DPP2q and DPP3q compounds with closed shell quinoidal ground states. Accordingly, we identified the aromaticity of the conjugated (hetero-)aromatic bridge to be key for modulating the electronic character of these biradicaloid compounds and achieved a spin crossover from closed shell quinones DPP2q and DPP3q to open shell biradical DPP1˙˙ as confirmed by optical and magnetic spectroscopic studies (UV/vis/NIR, NMR, EPR) as well as computational investigations (spin-flip TD-DFT calculations in combination with CASSCF(4,4) and harmonic oscillator model of aromaticity (HOMA) analysis). Spectroelectrochemical studies and comproportionation experiments further prove the reversible formation of mixed-valent radical anions for the DPP2q and DPP3q quinoidal compounds with absorption bands edging into the NIR spectral region. |
format | Online Article Text |
id | pubmed-8179021 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2020 |
publisher | The Royal Society of Chemistry |
record_format | MEDLINE/PubMed |
spelling | pubmed-81790212021-06-22 Tuning phenoxyl-substituted diketopyrrolopyrroles from quinoidal to biradical ground states through (hetero-)aromatic linkers Rausch, Rodger Röhr, Merle I. S. Schmidt, David Krummenacher, Ivo Braunschweig, Holger Würthner, Frank Chem Sci Chemistry Strongly fluorescent halochromic 2,6-di-tert-butyl-phenol-functionalised phenyl-, thienyl- and furyl-substituted diketopyrrolopyrrole (DPP) dyes were deprotonated and oxidised to give either phenylene-linked DPP1˙˙ biradical (y(0) = 0.75) with a singlet open shell ground state and a thermally populated triplet state (ΔE(ST) = 19 meV; 1.8 kJ mol(−1); 0.43 kcal mol(−1)) or thienylene/furylene-linked DPP2q and DPP3q compounds with closed shell quinoidal ground states. Accordingly, we identified the aromaticity of the conjugated (hetero-)aromatic bridge to be key for modulating the electronic character of these biradicaloid compounds and achieved a spin crossover from closed shell quinones DPP2q and DPP3q to open shell biradical DPP1˙˙ as confirmed by optical and magnetic spectroscopic studies (UV/vis/NIR, NMR, EPR) as well as computational investigations (spin-flip TD-DFT calculations in combination with CASSCF(4,4) and harmonic oscillator model of aromaticity (HOMA) analysis). Spectroelectrochemical studies and comproportionation experiments further prove the reversible formation of mixed-valent radical anions for the DPP2q and DPP3q quinoidal compounds with absorption bands edging into the NIR spectral region. The Royal Society of Chemistry 2020-11-11 /pmc/articles/PMC8179021/ /pubmed/34163813 http://dx.doi.org/10.1039/d0sc05475e Text en This journal is © The Royal Society of Chemistry https://creativecommons.org/licenses/by/3.0/ |
spellingShingle | Chemistry Rausch, Rodger Röhr, Merle I. S. Schmidt, David Krummenacher, Ivo Braunschweig, Holger Würthner, Frank Tuning phenoxyl-substituted diketopyrrolopyrroles from quinoidal to biradical ground states through (hetero-)aromatic linkers |
title | Tuning phenoxyl-substituted diketopyrrolopyrroles from quinoidal to biradical ground states through (hetero-)aromatic linkers |
title_full | Tuning phenoxyl-substituted diketopyrrolopyrroles from quinoidal to biradical ground states through (hetero-)aromatic linkers |
title_fullStr | Tuning phenoxyl-substituted diketopyrrolopyrroles from quinoidal to biradical ground states through (hetero-)aromatic linkers |
title_full_unstemmed | Tuning phenoxyl-substituted diketopyrrolopyrroles from quinoidal to biradical ground states through (hetero-)aromatic linkers |
title_short | Tuning phenoxyl-substituted diketopyrrolopyrroles from quinoidal to biradical ground states through (hetero-)aromatic linkers |
title_sort | tuning phenoxyl-substituted diketopyrrolopyrroles from quinoidal to biradical ground states through (hetero-)aromatic linkers |
topic | Chemistry |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8179021/ https://www.ncbi.nlm.nih.gov/pubmed/34163813 http://dx.doi.org/10.1039/d0sc05475e |
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