Syntheses, Crystal Structures and Properties of Three Metal Complexes Based on 3,3′,4,4′-Tetracarboxyazobenzene

Three transition metal complexes based on H4ddb ligand, namely[Co-2(ddb)(phen)(2)(H2O)(6)]center dot 3H(2)O (1), [Co(ddb)(0.5)(bpy)(0.5)(H2O)(3)](n) (2) and {[Ag(dpe)]center dot(0.5)(H(2)ddb)center dot H2O}(n) (3). (H(4)ddb=3,3',4,4'-tetracarboxyazobenzene, bpy=4, 4'-pyridine, dpe=1, 2-di(4-pyridyl) ethylene) have been synthesized and structurally characterized by elemental anal-yses, IR spectroscopy, powder X-ray diffraction and single-crystal X-ray diffraction analyses. Complex 1 is binuclear structure, which is linked into 3D supramolecular network through rich hydrogen bonding interactions. Complex 2 shows 2D network constructed from Co2+ ion cross-linked by ddb(4-) ligands via mu(4):eta(1), eta(1), eta(1), eta(1) coordina-tion mode. Complex 3 is linear chain structure based on Ag(I) ion and dpe ligands. Interestingly, the guest molecule H(2)ddb(2-) extends a 3D supramolecular structure of 3 through intermolecular hydrogen bonding interactions. In addition, the thermal stabilities and luminescence properties of 1 similar to 3 were also studied. CCDC: 1861508, 1; 1861509, 2; 1861510, 3.