Bis(perfluoroaryl)chalcolanes Ar(2)(F)Ch (Ch = S, Se, Te) as ?/?-Hole Donors for Supramolecular Applications Based on Noncovalent Bonding

Perfluorinated arenes (perfluoropyridine, perfluor-otoluene, and perfluorobiphenyl) were converted to the bis-(perfluoroaryl)chalcolanes ArF2Ch (Ch = S 59-88%, Se 54-84%, Te 10-41%) via the developed one-pot methodology. This method includes the generation of Na2Ch (formed in situ by the reduction of Ch with the system Na+[C10H8]center dot-) followed by its treatment with any one of the arenes. The crystal structures of (4-NC5F4)2S (2), (C12F9)2S (3) (p-CF3C6F4)2Se (4), (C12F9)2Se (6A,B; two polymorphs), (C12F9)2Te (9), and (4-NC5F4)2Te (8B; a novel polymorph) were determined by X-ray crystallography. In the solid state, compounds ArF2Ch are self-associated via sigma-(Ch)-hole interactions with F (or N for 8B) and also pi-pi stacking between the arenes. The sigma/pi-hole donor properties of ArF2Ch were evaluated by molecular electrostatic potential surface analysis using the density functional theory approach. The maximum Vs(sigma-hole) values (from +25 to +38 kcal/mol) increase in the order S < Se < Te along with an increase in the polarizability and decrease in the electronegativity of the Ch sites, while the pi-hole depths (+14 to +20 kcal/mol) follow the opposite trend being the lowest for the TeII derivatives.