Abstract

As part of a survey on the influence of fused aromatic rings on the porphyrin chromophore, a series of novel structures with fused acenaphthylene or benzothiadiazole rings have been synthesized. Base-catalyzed condensation of 1-nitroacenaphthylene or 4-nitrobenzothiadiazole with esters of isocyanoacetic acid afforded good yields of the annelated pyrroles 5 and 28. Cleavage of the ester moieties with KOH in refluxing ethylene glycol gave the unsubstituted heterocycles, and subsequent condensation with 2 equiv of acetoxymethylpyrroles 9 in acetic acid/ethanol produced the modified tripyrranes 12 and 31. Tripyrranes with terminal tert-butyl ester units were treated with TFA and condensed with 3,4-diethyl-2,5-pyrroledicarboxaldehyde 13 in dichloromethane to give, following oxidation with DDQ, the corresponding π-extended porphyrins 14 and 32. Acenaphthoporphyrins 14 showed unique UV−vis spectra with a triply split Soret band region and a relatively strong band near 660 nm. Strongly red-shifted absorptions wer...

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call