Novel intramolecular π–π-interaction in a BODIPY system by oxidation of a single selenium center: geometrical stamping and spectroscopic and spectrometric distinctions

Abstract

A new BODIPY system displaying an intramolecular π–π-interaction was synthesized and studied. When the selenium center was oxidized, the substituted phenyl group undergoes π–π stacking with one side of the BODIPY core. The oxidized form showed, not only a down-field shift in the NMR peak, but also splitting due to geometrical changes that arise when going from C_s to C₁. The compound was characterized by X-ray diffraction; DFT methods helped elucidate the influence of the unexpected π–π stack and its connection to the photophysical properties imparted by the Se oxidation.