Crystal Structure Analysis and Conformational Isomerism of 2,2′-(4,4′-oxybis(4,1-phenylene)bis(azan-1-yl-1-ylidene))bis(methan-1-yl-1-ylidene)dinaphthalen-1-ol

Abstract

A helicate Schiff base ligand 2,2′-(4,4′-oxybis(4,1-phenylene)bis(azan-1-yl-1-ylidene))bis(methan-1-yl-1-ylidene)dinaphthalen-1-ol (NDADPE) was synthesized from 1-hydroxynaphthalene-2-carbaldehyde and 4-(4-aminophenoxy)benzenamine. The compound (NDADPE) was characterized by FT-IR, 1H NMR, and mass spectroscopic and elemental analyses. The structure of NDADPE was solved by single crystal X-ray diffraction method. The crystal structure reveals that there are two conformers (A and B). Conformer A forms a supramolecular dimer with bifurcated C‒H···O hydrogen bond synthon, whereas conformer B forms a supramolecular helix due to bifurcated C‒H···O hydrogen bond synthons. Hirshfeld surface analyses were carried out on the two conformers to explain the conformational isomerism.