Live long and phosphor : synthesis of new 2,1,3-benzothiadiazole based scaffolds and novel organo-Au(I) luminophores

Sammanfattning: 2,1,3-Benzothiadiazole (BTD) has arisen as a scaffold of interest to a variety of fields including materials chemistry and medicinal chemistry. It is utilized in the development of light emitting materials, solar-cells, and batteries. This work describes the synthesis of new BTD derivatives with substitution patterns that are not commonly seen in publications that mention BTD-based materials. These substitutions are primarily based on functionalizations accessed through iridium catalyzed C–H borylation and subsequent oxidation with OXONE®. The selectivity arising from the C–H borylation of BTD has inspired further modifications of the BTD backbone in ways not previously explored. The borylation of BTD has allowed for the direct auration of this heteroaromatic core. Transmetalation of benzo[2,1,3]thiadiazol-4-ylboronic acid with five different Au(I) salts leads to the formation of aurated BTD complexes with a series of distinct coordinating ligands (PPh3, PtBu3, PCy3, IPr and IMes). Herein the synthesis of five BTD–Au(I)–L complexes is described and their structure was confirmed by NMR and X-ray diffraction. Aryl–Au(I) complexes have found uses in a variety of fields but their photophysical characterization is generally lacking, so the photophysical properties of the five synthesised complexes were studied by a variety of steady state and time-resolved methods. These structures represent the first BTD Au(I) complexes where a Au(I) is directly bound to the BTD backbone. They exhibit complex luminescence profiles in solution deriving from the interaction of the BTD π system and the Au(I) atom.