Gradual reactivity in tert -butyl seleno-thio-catechol

The selective reactivity of the selenol unit in the presence of the neighboring thiol functionality in t-BuC6H3(SH)(SeH) was investigated in this work. Compound t-BuC6H3(SH)(SeH) can undergo oxidation in air, forming the homocoupled diselane (t-BuC6H3(SH)Se)2, which was characterized by NMR. The partially deprotonated derivatives t-BuC6H3(SH)(SeH)∙½TMEDA and (t-BuC6H3(SH)Se)2∙½TMEDA of compounds t-BuC6H3(SH)(SeH) and (t-BuC6H3(SH)Se)2 were characterized by XRD analysis. Additionally, a site-selective pKa analysis of t-BuC6H3(SH)(SeH) was performed using a density functional theory (DFT) based thermodynamic cycle to evaluate and quantify the relative acidity of the SH and SeH functional groups in the presence of one another. Moreover, the redox behavior of compound t-BuC6H3(SH)(SeH) was characterized by cyclic differential pulse voltammetry (CDPV) measurements.