Helical ullazine-quinoxaline-based polycyclic aromatic hydrocarbons
Polycyclic aromatic azomethine ylides (PAMYs) are powerful building blocks in the bottom-up synthesis of internally nitrogen-containing polycyclic aromatic hydrocarbons (N-PAHs) through 1,3-cycloaddition reactions. In this work, the cycloaddition reaction of PAMYs to asymmetric ortho-quinones is pre...
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| Main Authors: | , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
2019
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| In: |
Chemistry - a European journal
Year: 2018, Volume: 25, Issue: 5, Pages: 1345-1352 |
| ISSN: | 1521-3765 |
| DOI: | 10.1002/chem.201804751 |
| Online Access: | Verlag, Volltext: http://dx.doi.org/10.1002/chem.201804751 Verlag, Volltext: https://onlinelibrary.wiley.com/doi/abs/10.1002/chem.201804751 |
| Author Notes: | Marcus Richter, Sebastian Hahn, Evgenia Dmitrieva, Frank Rominger, Alexey Popov, Uwe H.F. Bunz, Xinliang Feng, and Reinhard Berger |
| Summary: | Polycyclic aromatic azomethine ylides (PAMYs) are powerful building blocks in the bottom-up synthesis of internally nitrogen-containing polycyclic aromatic hydrocarbons (N-PAHs) through 1,3-cycloaddition reactions. In this work, the cycloaddition reaction of PAMYs to asymmetric ortho-quinones is presented, which, in contrast to the addition to symmetric para-quinones, facilitates subsequent condensation reactions and allows the synthesis of three helical N-PAHs with ullazine-quinoxaline (UQ-1-3) backbones. UQ-1 and UQ-2 possess two helical centers; however, single-crystal X-ray analysis together with the computational modeling of UQ-3 elucidate the formation of only the thermodynamically most stable geometry with four helical centers in a (P,P,M,M) configuration. For the series UQ-1-3, the number of redox steps is directly correlated with the number of ullazine or quinoxaline units incorporated into the targeted molecular backbones. A detailed investigation of the spectroscopic and magnetic properties of the radical cation and anion as well as the dication and dianion species by in situ EPR/UV/Vis-NIR spectroelectrochemistry is provided. The excellent optical and redox properties combined with helical geometries render them possibly applicable as chiral emitter or ambipolar charge transport material in organic electronics. |
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| Item Description: | First published: 05 November 2018 Gesehen am 28.02.2019 |
| Physical Description: | Online Resource |
| ISSN: | 1521-3765 |
| DOI: | 10.1002/chem.201804751 |