Syntheses, Crystal Structures, and Properties of Six Coordination Complexes Based on a Newly Designed Mercapto-thiadiazole Ligand

Abstract

Six coordination complexes were solvothermally synthesised: a 3D framework [Cd(tmtt)2]n (1), 2D architectures [Zn(tmtt)2]n (2) and [Pb(tmtt)2]n (3), 1D chain structures [Ni(tmtt)2·(H2O)2]n (4) and [Co(tmtt)2·(H2O)2]n (5), and a mononuclear structure [Hg(tmtt)2] (6). The complexes, based on self-assembly of different metal ions with a newly designed mercapto-thiadiazole ligand tmttH (tmttH = 5-[(1H-1,2,4-triazol-1-yl)methyl]-1,3,4-thiadiazole-2(3H)-thione), were characterised by single crystal X-ray diffraction analyses. Crystal structure analyses reveal that complex 1 exhibits a four-fold interpenetrating 3D framework with {64.82} topology based on two kinds of right-handed single-helical chains, 2 displays a bilayer structure, 3 presents a crown-shaped network, 4 and 5 show 1D double–helical chain structures, and 6 is a mononuclear structure. Moreover, the thermal stabilities of crystalline samples 1–6 have been investigated, and the luminescent properties of complexes 1, 2, 3, 6, and the free ligand have been studied. The results of photoluminescent measurements illustrate that 2 and 3 may serve as excellent candidates for potential photoactive materials.