Synthesis Characterization and Protonation Behavior of Quinoxaline-Fused Porphycenes

摘要

9,10-Quinoxaline-fused porphycenes >1a-H2 and >1b-H2 were synthesized by intramolecular McMurry coupling. As a result of the annulation of the quinoxaline moiety on the porphycene skeleton, >1a-H2 and >1b-H2 display absorption and fluorescence in the near infra-red (NIR) region. Additionally, the quinoxaline moieties of >1a-H2 and >1b-H2 act as electron-withdrawing groups, introducing lower reduction potentials than for pristine porphycene. The protonation occurred at the nitrogen atoms in the cavity of freebase porphycenes and at the quinoxaline moieties for their nickel complexes to give diprotonic species.