Probing the Generation of Reactive Species from Surfactants with Interface-Sensitive Mass Spectrometry Studies

Abstract We report the first observation of a hypervalent nitrogen species stabilized in the condensed phase with a lifetime on the order of minutes, formed via homolytic N–Br bond cleavage in a gemini surfactant at the air-liquid interface. The interfacial environment, shaped by entangled hydrophobic-hydrophilic surfactant structures resembling porous membranes, promotes radical formation over ionic dissociation. Simultaneously, we explore the unique interfacial behavior of Zn2+ compared to other transition metals using Field-Induced Droplet Ionization (FIDI). Zn2+ alone exhibits distinct speciation at the interface, forming a stable complex with three ethanol ligands—a behavior attributed to its electronic configuration and optimal polarity. Together, these findings highlight how interfacial architecture and specific ion properties can stabilize otherwise transient species and open pathways for designing controlled-release systems for reactive intermediates.