Crystal Engineering Approach to Generate Crystalline Inclusion Compounds in Which 5-Hydroxyisophthalic Acid Serves as a Host

A series of seven crystalline inclusion compounds (CICs) in which 5-hydroxyisophthalic acid (HPA) serves as a host has been isolated. HPA self-assembles to consistently form 2-D hydrogen bonded networks with distorted honeycomb (hcb) topology when crystallized in the presence of guest molecules that contain a carbonyl moiety. In each of the seven structures, the hcb networks formed by HPA contain a phenolic OH group that is exposed to the walls of channels formed by stacking of the hcb networks. These phenolic moieties interact with the carbonyl group of guest molecules via OH (phenol)···O (carbonyl) hydrogen bonding. The consistency of the crystal packing herein is in contrast to the promiscuity in previously reported HPA crystal structures and suggests that HPA can serve as a host for a wide range of guests.