Institution: | 1. Aix Marseille Univ, CNRS, CINaM, Marseille, France;2. Department of Chemistry (“Giacomo Ciamician”), University of Bologna, Via Selmi, 2, 40126 Bologna, Italy
Institute for Microelectronics and Microsystems, Italian National Research Council, Section of Bologna, Via Piero Gobetti 101, 40129 Bologna, Italy
Contribution: Investigation (equal);3. Aix Marseille Univ, CNRS, Centrale Marseille, FSCM, Marseille, France;4. Department of Chemistry (“Giacomo Ciamician”), University of Bologna, Via Selmi, 2, 40126 Bologna, Italy
Contribution: Investigation (supporting) |
Abstract: | The synthesis of regioisomeric asterisks ( 5 ) and ( 6 ) incorporating a benzene core with six 1-naphthylthio or six 2-naphthylthio arms are reported in search for new materials with optoelectronic properties. The consequences on the extension of a π system surrounding a persulfurated benzene core provide a new avenue to study the structural, photophysical, and chemical properties of such family of all-organic phosphors. It also diverts the persulfuration mechanism after two radical cyclizations for making a 5]dithiohelicene by-product ( 7 ) and favors dynamic sulfur component exchange reactions surrounding the core. These exchanges convert asterisks ( 5 ) and ( 6 ), non-phosphorescent at 20 °C to the highly phosphorescent ( 4 ) (ϕ ∼100 %, solid state at 20 °C). For asterisks ( 5 ) and ( 6 ), the absence of the typical phosphorescence of the per(phenylthio)benzene core in the solid state at 20 °C and the presence of a weak naphthalene-based phosphorescence at 77 K is attributed to an energy transfer from the triplet state of the persulfurated benzene core to the outer naphthalene moieties, resulting in an antenna system. |