Synthesis and solid-state self-assembly of polyphenols

Abstract

A simple synthetic strategy for polyphenols (1-3) is outlined, and their crystallographic investigations are described. Interesting self-assembled structures were observed in the crystal lattice owing to the 3D structure and hydrogen-bonding interactions between the hydroxyl groups. In the crystal lattice of trisphenol 1, each hydroxyl group participates in forming monohelical chains of hydrogen bonds along the a-axis. Each molecule of trisphenol 1 is linked to six adjacent molecules through O-H⋯O hydrogen bonds. In the crystal lattice of trisphenol 2, each molecule is linked to six symmetrically oriented trisphenol neighbors through a total of six hydrogen bonds, thereby creating a distorted ladder-type hydrogen bonded chains. Pentaphenol 3 crystallizes as tetrahydrate and water molecules are incorporated into the crystal lattice through the formation of cyclic water hexamer with a chair conformation. In all the above structures, both the number and the position of the hydroxyl groups on the triphenylmethane core play an important role in the formation of supramolecular architectures.