2,4,5,7,9,10-Hexaethynylpyrenes: Synthesis, Properties, and Self-Assembly

A series of 2,4,5,7,9,10-hexaethynylpyrenes
was synthesized using
2,7,9,10-tetrabromopyrene-4,5-dione as the key intermediate. The effects
of the position and number of the ethynyl groups on the physicochemical
properties of the corresponding pyrenes were clarified by comparison
with 4,5,9,10-tetraethynylpyrene and 2,7-diethynylpyrene derivatives.
The prepared hexaethynylpyrenes that bear benzene moieties self-assemble
via π–π stacking in solution and/or the condensed
phase.