Syntheses, crystal structure, luminescent properties and Hirshfeld surface of a set of triazole-based salts

Abstract

To further investigate and explore the new luminescent materials, three new salts with triazole-based skeletons, namely, [HCNT]+X− (X = BS (1), PS (2) and SS∙H2O (3)) [CNT = 4-((1H-1,2,4-triazol-1-yl)methyl)benzonitrile, BS= benzene-sulfonic acid, PS = p-methyl phenyl sulfonic acid, SS = sulfosalicylic acid], have been prepared through the CNT and three sulfonic acids, respectively. Compounds 1-3 have been characterized by single–crystal X–ray diffraction, IR, UV-Vis, EA, powder X-ray diffraction (PXRD) and thermogravimetric analysis (TGA). In the target compounds, hydrogen bonds (N/O/C–H⋯O/N) and stacking interactions can be evidently observed, through which a three-dimensional framework will be built. The luminescent spectra of these compounds show that the maximal emission peaks in compounds 1-3 can be found to be 452, 441 and 472 nm, respectively. Compared with the free CNT, the emission maxima of compounds 1-3 are obviously red-shifted about 135, 124 and 155 nm, respectively. The Hirshfeld surface analysis further confirms that the C∙∙∙C close contacts can account for the photoluminescent spectra.