SELF-RECOGNITION IN THE CRYSTAL-CHEMISTRY OF N,N'-BIS(3-HYDROXYPHENYL)ISOPHTHALAMIDE

The synthesis, characterization, and crystal chemistry of N,N'-bis(3-h ydroxyphenyl)-isophthalamide is described. Through a combination of si ngle-crystal X-ray diffraction, molecular orbital, and crystal packing calculations, the important intermolecular interactions have been det ermined. The structure contains examples of the more important nonbond ed contacts including O-H ... O hydrogen bonding, C-H ... O special hy drogen bonds, pi-pi stacking, N-H ...pi and aromatic edge-to-face inte ractions. The two pendent amidophenolic units of the molecule adopt di fferent conformations, one syn and one anti. In the solid state these conformations exclusively recognize each other forming syn-syn and ant i-anti hydrogen-bonded pairings. There are no examples of sun-anti hyd rogen-bonding pairs. The structure consists of columns that are made u p of anti-anti hydrogen-bonded pairs held together by pi-pi stacking i nteractions. These columns are linked by the syn-syn hydrogen-bonding pairs. Lattice energy calculations suggest that the anti-anti, syn-syn , and pi-pi interactions are equally important in the formation of the solid-state structure.