Optical and electrochemical properties of ethynylaniline derivatives of phenothiazine, phenothiazine-5-oxide and phenothiazine-5,5-dioxide.

Three phenothiazine (PTZ) derivatives with varying degrees of sulfur oxidation states were synthesized as strong electron donors. The thioether, sulfoxide and sulfone PTZ-derivatives exhibited irreversible oxidation at 0.19 V, 0.