3-(benzo[d]thiazol-2-YL)phenol and 4-(benzo[d]thiazol-2-YL)phenol: Crystal Structure Determination, DFT Calculations and Visualizing Intermolecular Interactions Using Hirshfeld Surface Analysis

This article describes the synthesis and X-ray crystal structure analysis of 3-(benzo[d]thiazol-2-yl) phenol (I) and 4-(benzo[d]thiazol-2-yl)phenol (II), crystallized in centrosymmetric triclinic and orthorhombic space groups respectively. The packing in the unit cell of these two positional isomers are different resulting difference in various types of intermolecular interactions (C-H…S, O-H…Ow and O-H…N) connect the molecules into 2D frameworks. Due to presence of lattice water in compound (I), H-bonding interactions are strong and melting point of (I) is comparatively higher than (II). The DFT optimized molecular geometries in (I) and (II) agree closely with those obtained from crystallographic studies. The compounds (I) and (II) have been crystallized in centrosymmetric space groups. The DFT optimized molecular geometries in both compounds agree closely with those obtained from the crystallographic studies. An interplay of O-H…Ow and O-H…N type strong hydrogen bonds and C-H…S type weak interactions connect the molecules of (I) and (II) into 2D framework. Hirshfeld surface analysis of (I) indicates that the H…H and H…π contacts can account for 47.4% and 18.7%, respectively, of the Hirshfeld surface area, whereas the corresponding fraction in (II) is 36.5% and 29.5%, respectively.