Photochemistry of N‐aryl and N‐alkyl dibenzothiophene sulfoximines

Abstract N ‐phenyl dibenzothiophene sulfoximine has been demonstrated to produce phenyl nitrene and dibenzothiophene S ‐oxide upon irradiation with UV‐A light, and dibenzothiophene S ‐oxide upon further irradiation releases triplet atomic oxygen. Thus, N ‐phenyl dibenzothiophene sulfoximine exhibits a rare dual‐release capability in its photochemistry. In this work, N ‐substituted dibenzothiophene sulfoximine derivatives are irradiated with UV‐A light to compare their photochemistry and quantum yield of dibenzothiophene S ‐oxide production with that of N ‐phenyl dibenzothiophene sulfoximine. Both N ‐aryl and N ‐alkyl derivatives of dibenzothiophene sulfoximine are examined to observe their effects on the quantum yield of the photolysis reaction. Adding electron withdrawing N ‐aryl substituents is shown to increase the quantum yield of dibenzothiophene S ‐oxide production, while adding electron donating N ‐aryl substituents is shown to decrease the quantum yield. The quantum yield was slightly lowered or not increased by most N ‐alkyl substituents. Furthermore, the quantum yield was not augmented by branching and steric hindrance effects associated with the N ‐alkyl substituents. These results suggest that electronic modulation of the sulfoximine bonds affects the observed photolysis reaction.