Crystal structure, Hirshfeld surface analysis and third-order nonlinear optical properties of supramolecular complexes of 18-crown-6 with 6-hydrazinonicotinichydrazide and p -phenylenediamine

The crystal structures of the host-guest supramolecular complexes [2(6-HPCH)2 +.3(18C6)].4[ClO4 over bar ].2(H2O) (I) and [(PDA)2 +.2(18C6)].2[Cl over bar ].10(H2O) (II) (18C6 = 18-crown-6; 6HPCH = 6-hydrazinylpyridine-1-ium-3-carbohydrazinium; PDA = p-phenylenediaminium) were determined by single-crystal X-ray diffraction analysis. Supramolecular assembly is constructed by N -H center dot center dot center dot O, O -H center dot center dot center dot O and C-H center dot center dot center dot O interactions. Both crys-tallize in the monoclinic system with centrosymmetric space group P2 1 / n . The vibrational patterns in FT-IR are used to identify the functional groups. Direct band gap energy estimated by diffuse reflectance spectrum are, 3.42 eV for (I) and 4.78 eV for (II). Molecular interactions are analyzed by Hirshfeld sur-faces, derived from single-crystal XRD data. Fingerprint plots of Hirshfeld surfaces were used to locate and analyze the percentage of hydrogen bonding interactions. A z-scan study was used to determine the third-order NLO response. (c) 2022 Elsevier B.V. All rights reserved.