| Summary: | The functionalization of <i>N</i>-(benzo[<i>d</i>]thiazol-2-yl)benzamide with a nitro (NO<sub>2</sub>) substituent influences the solid-state arrangement, absorption and fluorescence properties of these compounds. Each of these compounds crystallised in a different crystal system or space group, namely a monoclinic crystal system with <i>P</i>2<sub>1</sub>/<i>n</i> and <i>C</i>2/<i>c</i> space groups for <i>o</i>-NO<sub>2</sub> and <i>m</i>-NO<sub>2</sub> derivatives, respectively, and an orthorhombic crystal system (<i>Pbcn</i> space group) for <i>p</i>-NO<sub>2</sub> derivative. The <i>o</i>-NO<sub>2</sub> substituent with intrinsic steric hindrance engendered a distorted geometry. Conversely, the <i>m</i>-NO<sub>2</sub> derivate displayed the most planar geometry among the analogues. The solid-state architectures of these compounds were dominated by the N−H···N and C−H···O intermolecular hydrogen bonds and were further stabilised by other weak interactions. The dimer synthons of the compounds were established via a pair of N−H···N hydrogen bonds. These findings were corroborated by a Hirshfeld surface analysis and two-dimensional (2D) fingerprint plot. The interaction energies within the crystal packing were calculated (CE-B3LYP/6-31G(d,p)) and the energy frameworks were modelled by CrystalExplorer17.5. The highly distorted <i>o</i>-NO<sub>2</sub> congener synthon relied mainly on the dispersion forces, which included π–π interactions compared to the electrostatic attractions found in <i>m</i>-NO<sub>2</sub>. Besides, the latter possesses an elevated asphericity character, portraying a marked directionality in the crystal array. The electrostatic and dispersion forces were regarded as the dominant factors in stabilising the crystal packing.
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