Syntheses, Characterization, and Crystal Structures of Nickel Complexes Derived From Tridentate Schiff Bases and Thiocyanate Mixed Ligands

Abstract

The self-assembly and construction of specific Schiff base nickel complexes are important in the exploration of new functional materials. In the present work, in the presence of thiocyanate ligands, two mononuclear Schiff base nickel(II) complexes, [NiL1(NCS)] (1) and [Ni(L2)₂] (2) (L1 = 2-bromo-6-[ (2-dimethylaminoethylimino)methyl]phenolate, L2 = 2-bromo-6-[(3-dimethylaminopropylimino)methyl]phenolate), with different coordination modes, have been synthesized and characterized by elemental analysis, IR spectra, and single-crystal X-ray diffraction. The Ni atom in (1) is four-coordinated in a square planar configuration, with three donor atoms of L1 and one nitrogen atom of thiocyanate ligand. The Ni atom in (2) is six-coordinated in an octahedral configuration, with six donor atoms from two L2 ligands. The relationship between the ligands and the final structures of the complexes is discussed.

Keywords:

• crystal structure
• mononuclear complex
• nickel complex
• Schiff base
• self-assembly