New saccharinate complexes with 3,3-azobispyridine ligand: synthesis, characterization, and spectroscopic properties

Abstract

The new metal complexes with saccharinate (sac) and 3,3-azobispyridine (3,3-abpy), [Ni(H2O)(4)(3,3-abpy)(2)](sac)(2) (1), [Cu(sac)(2)(H2O)(-3,3-abpy)](n) (2), [Zn(H2O)(4)(3,3-abpy)(2)](sac)(2) (3), [Cd(sac)(2)(H2O)(2)(-3,3-abpy)](n) (4), and [Hg-2(-sac)(2)(sac)(2)(-3,3-abpy)(3,3-abpy)(2)](n) (5), were synthesized and characterized by IR spectra, elemental analysis, and single-crystal X-ray diffraction. Spectroscopic (UV-vis and photoluminescence) and thermal properties were also investigated. Single-crystal X-ray analysis reveals that Ni(II) and Zn(II) are coordinated by four aqua ligands and two nitrogens of 3,3-abpy, while sac is a counter-ion in 1 and 3. In 2, Cu(II) and all ligands are linked by coordination bonds and 3,3-abpy ligands connect the Cu(II) centers forming a 1-D coordination polymer. In 4, sac N-coordinated to Cd(II) and distorted octahedral geometry of Cd(II) ion is completed by two aqua and bridging 3,3-abpy ligands. In 5, sac bridges two Hg(II) ions to generate dinuclear [Hg-2(-sac)(2)] units. These dinuclear units are connected by 3,3-abpy to form a 1-D coordination polymer. The photoluminescence spectra of 3 and 5 show blue fluorescent emission bands, and these emissions can probably be assigned to intraligand fluorescent emissions. Thermal decompositions of the compounds are also discussed. For all complexes, magnetic susceptibility measurements show expected magnetic behavior. [GRAPHICS]