Synthesis and structural characterization of three saccharinate-metal complexes with exo-bidentate bis(imidazole) derivatives

Three coordination compounds, [Ag2(L1)(sac)2] center dot 5(H2O) (1, L1 = bis(N-imidazolyl)methane, sac = saccharinate), [Ag(L2)(sac)], (2, L2 = 1,4-bis(N-imidazolyl)butane), and [Cu(L2)2(H2O)2](sac)2 center dot 2(H2O) (3), were obtained from self-assembly of the metal salts with bis-imidazole ligands in the presence of saccharinato ion. All products were formed in solution and obtained by slow evaporation. Their structures were fully characterized by X-ray diffraction (XRD) analysis, Fourier transform infrared spectroscopy, elemental analysis, and thermogravimetric analyses. Compound 1 is a linear dinuclear complex, consisting of two Ag(sac) units bridged by a bis(N-imidazolyl)methane, while 2 is a tri-coordinated Ag(I) complex, with Ag(I) surrounded by three nitrogens in trigonal plane geometry. Compound 2 displays a 1-D wavy chain structure. XRD analysis revealed that 3 exhibits 1-D cationic double-stranded chain structure from doubly bridged [Cu(H2O)2] units. All these complexes display 3-D framework structures from a number of non-conventional weak interactions. IR spectra, elemental analyses, and thermal analyses are in good agreement with the crystal structure.