Host–Guest Complexes of Pentiptycene Receptors Display Edge-to-Face Interaction

The pentiptycene receptors form edge-to-face complexes
with a variety
of aromatic guests including nitroaromatics. X-ray diffractometry
revealed that compounds 1, 2, and 3 form host–guest assemblies with a thienyl fragment
(from a neightboring molecule of 1), benzene and nitrobenzene,
respectively. X-ray studies of the three crystal structures reported
here strongly suggest the edge-to-face to be a predominant binding
mode between the aromatic guests and electron-rich faces of the pentiptycene
aromatic cavity.