Question

What does excited state potential tell you about the pyrylium?

Answer 1

Pyrylium are aryl compounds with one oxygen atom in the six membered ring. These aromatic compounds, specially the 2,4,6 substituted pyrylium salts are very good electron transfer photoorganocatalysts. Hence, these are extensively used in synthesis.

Upon absorption of light, pyrylium compounds are excited to singlet state species and have mostly high excited state reduction potential. Thus, they are capable of oxidizing a wide range of organic compounds like alkenes, alkynes, ethers, phosphines and many more. The potential can vary depending on the electron donating or electron accepting nature of the substituent. But all of them have high reduction potential. And this makes them an excellent oxidant species resulting in wide use in synthesis as photoorganocatalyst.

Also, these compounds can act as good oxidant species in triplet excited state as well.