No abstract

Desilylative C(sp2)-C(sp2) cross-coupling reactions of arylsilanes with aryldiazonium salts under Au(i)/photoredox catalysis have been reported. The addition of Cu-salts as catalysts was found to be crucial for the success of this transformation.

Five new binary co-crystals have been prepared through molecular self-assembly of π-electron-rich molecules, such as phenanthrene, benzo[c]cinnoline, and phenazine, in the presence of π-electron-deficient molecules, such as tetrafluoro-1,4-benzoquinone, tetrachloro-1,4-benzoquinone, and 1,2,4,5-tetracyanobenzene, taken in an equimolar ratio. Crystal structure analysis revealed that in three binary co-crystals the constituent molecules were alternately sandwiched in a cofacial arrangement through π•••π interactions, whereas in the remaining two binary co-crystals the constituent molecules were aligned in a unique edge-to-face manner through lp•••π interactions. Co-crystals with π-stacking arrangement were fluorescent, whereas almost complete quenching of luminescence was observed in those having edge-to-face alignment of molecules. The photophysical observations of these co-crystals have been demonstrated via energetic quantification of the intermolecular interaction topology, which provides a molecular level understanding of factors controlling their solid-state absorption and luminescence behavior.

σ- and π-hole directed intermolecular interaction driven tuning of luminescence.