X-ray, Hirshfeld surfaces analyses, DSC-TGA thermal stability, infrared, and optical properties studies of phenylammonium tetrachlorozincate hydrate (C6H5NH3)2ZnCl4•H2O

This paper reports the synthesis, crystal structure reinvestigation at 296 K, Hirshfeld surfaces, DSC, TG-dTG, Infrared, and UV studies of (C6H5NH3)(2)ZnCl4 center dot H2O, which crystalized in the triclinic space group P-1 [Z = 2, a = 7.575(3) angstrom, b = 9.894(3) angstrom, c = 13.101(4) angstrom, alpha = 95.903(13)degrees, beta = 102.408(14)degrees and gamma = 111.659(13)degrees]. The crystal structure consists of two cations C6H5NH3+ linked to a distorted ZnCl42- tetrahedron anion, together linked to the water molecule via hydrogen bonds of N-H center dot center dot center dot Cl, N-H center dot center dot center dot O and O-HW center dot center dot center dot Cl types. The ZnCl42- tetrahedra and H2O molecules form an infinite two-dimensional layer parallel to (0 0 2) plan between the organic sheets. The powder and single-crystal X-ray analyses confirm the pure phase of the synthetized compound. The Hirshfeld surfaces and fingerprint plots, used to analyse quantitatively the interactions in the crystal structure, showed that Cl center dot center dot center dot H/H center dot center dot center dot Cl contacts due to O-H center dot center dot center dot Cl and N-H center dot center dot center dot Cl hydrogen bonding are the major contributor in the total crystal packing surface of (C6H5NH3)(2)ZnCl4 center dot H2O. The DSC-TGA analyses showed that the compound dehydration made at around 80 degrees C, gives an anhydrous compound thermally stable between 80 degrees C and 120 degrees C. The anhydrous compound decomposition process is predicted, and confirmed by Infrared spectra at various temperatures. The observed bands are assigned and discussed based on the theoretical analyses; the non-fundamental bands resulted in the formation of hydrogen bonding are assigned. The photoluminescence spectra investigated at room temperature showed a red emission line at 2.60 eV, which may be associated with radiative recombination of exciton confined within the ZnCl42-. This suggests potential applications for this compound as UV detection and optical materials.