Lone Pair–π Interaction‐Assisted Oxidative Conversion of SO 2 to Sulfate by a Phenyl‐Appended Redox‐Active Cu(II) Koneramine Complex

In this study, we have reported an approach to convert SO 2 gas into sulfate dianions using a phenyl‐appended koneramine complex. The Cu(II) koneramine complex [Cu(L Ph )Cl 2 ] was designed such that the incorporation of the phenyl moiety on the tertiary nitrogen of the koneramine backbone could facilitate weak interactions with sulfur dioxide (SO 2 ). At the same time, the redox‐active copper(II) ion enables electron transfer to SO 2 upon addition of ferrocene, thereby forming sulfate dianions in the presence of atmospheric oxygen at room temperature. Control reactions were performed with [Zn(L Ph )Cl 2 ] to establish the necessity of a redox‐active metal for facilitating electron transfer. Furthermore, investigations with carbon disulfide (CS 2 ) showed no conversion by [Cu(L Ph )Cl 2 ]. Control experiments employing electronic absorption spectroscopy, cyclic voltammetry, and electrospray ionization spectrometry were conducted to provide mechanistic insights into these processes.