Characterization of the adducts of bis(O-isoamyldithiocarbonato)nickel(II) with heterocyclic amines and X-ray structure of bis(O-isoamyldithiocarbonato)-bis(3-bromopyridine)nickel(II)

Resumo

A series of six-coordinated Ni(II) complexes, with the general formula Ni(Xan)L₂ (where Xan = = isoamyldithiocarbonato and L = 2-bromopyridine, 3-bromopyridine, 4-acetylpyridine, 3-hydroxypyridine and 2-methoxypyridine) are synthesized and characterized by the elemental analysis and various physicochemical techniques such as magnetic susceptibility and conductivity measurements, UV-visible and infrared spectral data. Based on the electronic spectra and magnetic susceptibility measurements, an octahedral geometry is proposed for all the complexes. IR spectral data show that in all these complexes substituted pyridines coordinate to the metal ion through nitrogen atoms occupying the fifth and sixth axial positions, whereas O-alkyldithiocarbonate acts as a monoanion bidentate ligand and occupies the planar positions of octahedral structures. The structure of the adduct with 3-bromopyridine is elucidated by the single crystal X-ray diffraction method. The complex crystallizes in the triclinic space group P-1 with unit cell parameters a = 6.5855(4) Å, b = 9.4984(6) Å, c = 12.4518(8) Å, α = 87.944(5)°, β = 78.843(5)°, γ = 77.794(5)°. The crystal structure of the molecule is stabilized by intermolecular C–H…S and C–H…π interactions.