Synthesis, characterization and X-ray crystal structures of [Ni(Me-sal)2dpt] and [Ni(Me-sal)dpt]Cl

Two Ni(II) complexes, [Ni(Me-sal)2dpt] (1) and [Ni(Me-sal)dpt]Cl (2), with penta- and tetradentate ligands ((H2L1)=H2(Me-sal)2dpt=N,N-bis(α-methylsalicylidene)dipropylenetriamine and (HL2)=H(Me-sal)dpt=N-(α-methylesalicylidene)dipropylenetriamine) containing N3O2 and N3O donor sets, respectively, have been synthesized and characterized by elemental analyses, FT-IR and UV–Vis spectroscopy. The green five coordinate complex [Ni(Me-sal)2dpt] (1) forms on reaction of H2(Me-sal)2dpt with NiII(OAc)2 · 4H2O in boiling methanol, whereas at reflux temperature in ethanol the red diamagnetic [Ni(Me-sal)dpt]Cl (2) is formed on reaction of H2(Me-sal)2dpt with NiCl2 · 6H2O. In the ligand (Me-sal)dpt one of the imine groups is hydrolysed resulting in a new tetradentate N3O ligand. Complex (2) is also prepared in a higher yield by the direct reaction of H(Me-sal)dpt with NiCl2 · 6H2O. The crystal and molecular structures of (1) and (2) were determined by X-ray crystallography. Complex (1) crystallizes in the monoclinic space group P21/c and complex (2) crystallizes in the triclinic space group P1¯. The coordination polyhedron about the Ni(II) center in complex (1) is best described as distorted trigonal bipyramidal and that of complex (2) as distorted square planar. The FT-IR and UV–Vis spectra of the complexes are also discussed.

Graphical abstractThe synthesis, characterization, and single-crystal X-ray diffraction studies for two new Ni(II) complexes, [Ni(Me-sal)2dpt] (1) and [Ni(Me-sal)dpt]Cl (2), with penta- and tetra-dentate ligands H2(Me-sal)2dpt and H(Me-sal)dpt containing N3O2 and N3O donor sets, respectively, are reported. The coordination polyhedron about the Ni(II) center in complex (1) is best described as distorted trigonal bipyramidal and that of complex (2) as distorted square planar containing a “half unit” ligand, (Me-sal)dpt.Figure optionsDownload full-size imageDownload as PowerPoint slide