AI Article Synopsis
- The compound 2,5-Bis(4-propyl-2-pyrrolyl)thiophene was used to synthesize large porphyrinoids, specifically dithiaamethyrin and trithianonaphyrin.
- X-ray crystallography revealed that dithiaamethyrin has a highly planar structure with a mean plane deviation of just 0.053 Å.
- The analysis indicated that the compound exhibits strong antiaromatic character, confirmed by a high NICS(0) value and a significant low field (1) H chemical shift for the inner NH proton at 24.0 ppm, demonstrating a greater antiaromaticity compared to other related compounds in different forms.
Article Abstract
2,5-Bis(4-propyl-2-pyrrolyl)thiophene was reacted with aryl aldehydes to afford large porphyrinoids; [24]dithiaamethyrin(1.0.0.1.0.0) and [36]trithianonaphyrin(1.0.0.1.0.0.1.0.0). X-ray crystallography of the dithiaamethyrin revealed a highly planar ring structure with mean plane deviation (MPD) value of 0.053 Å. A large positive NICS(0) value (+13.9 ppm) calculated for this planar 24π system unambiguously indicates an antiaromatic character that is consistent with a remarkably low field (1) H chemical shift of the inner NH proton at 24.0 ppm. The magnitude of the paratropic ring current effect in the 24π amethyrin framework in the free base form and the diprotonated form was discussed on the basis of the MPD value and the NICS value. The present dithiaamethyrin is much more strongly antiaromatic than the dodecaalkylamethyrin in their free base forms, but the order inversed in their diprotonated forms.
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| http://dx.doi.org/10.1002/asia.201403126 | DOI Listing |
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