Transannular S...N inter­actions in 10-ethynyl-10H-pheno­thia­zine 5-oxide and 5,5-dioxide

The title compounds are oxidation products of the parent compound 10-ethynyl-10H-pheno­thia­zine and differ with respect to transannular S...N inter­actions, the intra­molecular S...N contact being shorter in the dioxide.