Hydrothermal synthesis and characterization of Zn(II), Cd(II) and Ag(I)-saccharinate complexes containing bis(imidazol) derivatives

Five mixed-ligand complexes, namely [Zn(sac)2(μ-obix)]n (1), {[Cd(sac)2(μ-obix)2]·2H2O}n (2), [Cd(sac)2(μ-pbix)(H2O)2]n (3), [Ag2(sac)2(μ-pbix)2] (4) and [Ag2(sac)2(μ-mbix)] (5) with saccharinate (sac) and three isomeric bis(imidazole) ligands (1,x-bis(imidazol-1-ylmethyl)benzene; x = 2, obix; x = 3, mbix and x = 4, pbix), have been synthesized and characterized by elemental analysis, IR spectroscopy and single crystal X-ray diffraction. Moreover, their thermal and photoluminescence properties have been studied in detail. Single crystal X-ray results show that the saccharinate ligand coordinates to the metal ions through nitrogen atoms in complexes 1 and 3–5, while it connects to the metal ion by the carbonyl oxygen atom in complex 2. Complexes 4 and 5 are dinuclear, while complexes 1–3 are 1D coordination polymers. In complexes 1–5, adjacent 1D chains are interlinked into a 3D network by hydrogen bonding, C–H⋯π and π⋯π interactions. The most striking features of complexes 4 and 5 are that they contain (C−H)⋯Ag and (CO)⋯Ag close interactions. Complexes 3–5 display blue emissions which are due to ligand to metal charge transfers.

Graphical abstractIn this study five new d10 metal complexes were synthesized with bis(imidazole) derivatives and sac ligands and characterized. Complexes 1–3 are 1D coordination polymers while complexes 4 and 5 are dinuclear structures. The most striking features of complexes 4 and 5 are the (C−H)⋯Ag and (CO)⋯Ag close interactions. Complexes 3–5 show blue emissions.Figure optionsDownload full-size imageDownload as PowerPoint slide