Solid State Assemblies of Cyclic Imides Tethered Hydroxy Benzoic Acids with Pyridine and Quinoline: Toward the Formation of Channels and Cavities

A series of inclusion compounds of different cyclic imides tethered hydroxy-benzoic acid hosts (1–8) with guests pyridine (I–IV) and quinoline (V–X) have been prepared and structurally characterized. Supramolecular aspects pertaining to the influence of guest molecules toward the formation of solid state network structures of hosts are described. Hydrogen bonding of both carboxylic acid and hydroxyl groups as well as π···π stacking of aromatic imide units led to the formation of channels of different dimensionalities in the supramolecular architectures of I–X. In these structures, the channels are occupied by the guest molecules that interact with both hydrogen bonding groups of host molecules via different types of hydrogen bond motifs. Thermogravimetric analyses correspond to the association of different numbers of guest pyridine or quinoline molecules with isomeric hydroxy-benzoic acid hosts. Solid state fluorescence spectra of hosts 1–8 are recorded which show emissions in the region of 412–516 nm. Overall this structural study represents the combined effects of π-stacking aromatic imide synthons and two hydrogen bonding carboxylic acid and hydroxyl functional groups in the presence of aromatic nitrogen containing guests to create fascinating supramolecular architectures.