The photochemistry and photophysics of papaverine N-oxide in polar aprotic
and protic solvents has been studied in detail. Complex energy and charge-t
ransfer phenomena between chromophores occur in papaverine, New photochemis
try for the papaverine N-oxide system is reported. Irradiation in protic me
dia results in the formation of an emissive charge-transfer state with ensu
ing intramolecular hydroxylation in high isolated yields (75-80%).