A Triphenylene-Based Triptycene with Large Free Volume Synthesized by Zirconium-Mediated Biphenylation

Biphenylation using (Li(THF)(4))(2)center dot Zr(biphe)(3) of hexabromotriptycenes bearing H (1-H) or Bu (1-Bu) at the bridgeheads gave triptycenes with triphenylene blades. The blades extend both perpendicular and parallel to the 3-fold axis and generate a large intramolecular free volume (IMFV) (1-H, AM1, 710 angstrom(3); cf. triptycene, AM1 71 angstrom(3)). Crystals of 1-H Could not be obtained. Triptycene 1-Bu, in which the Bu (groups fill the voids near the bridgehead, was crystalline. X-ray diffraction analysis revealed crystal packing with alternating interlocked corrugated and distorted hexagonal layers.