Three Coordination Compounds Based on the Rigid N-Donor Ligand: Syntheses, Crystal Structures, Hirshfeld Surface Analyses and Luminescent Properties

Three new coordination compounds, [Zn₂(Dpb)(2-Btc)(OH)]_n·0.5nH₂O (Ι), [Cd₂(Dpb)₂(m-Bdc)₂]_n (II), [Cd(Dpb)(HBtc)(H₂O)₂]·H₂O (III) (Dpb = 2,6-di(pyrazin-2-yl)-4,4'-bipyridine, H₃(2-Btc) = benzene-1,2,4-tricarboxylic acid, m-H₂Bdc = 1,3-benzenedicarboxylic acid, H₃Btc = benzene-1,3,5-tricarboxylic acid), were designed and synthesized. Their structures have been characterized by elemental analyses, infrared spectra and X-ray single-crystal diffraction analyses (CCDC nos. 2373881 (Ι), 2080659(II) and 2373880 (III)). Compound Ι and II exhibit 2D structure, and compound III shows a mononuclear structure. The differences in the structures of Ι–III reveal that the auxiliary ligand exerts an important effect on the ultimate structures. Moreover, Hirshfeld Surface analysis of coordination compounds Ι–III were performed by Crystal Explorer 21 program. Furthermore, the solid-state luminescence emissions, the fluorescence decays and the CIE chromaticity coordinates of Ι–III were also investigated.