Anion-Controlled Syntheses, Characterization, and Crystal Structures of Four Schiff Base Zinc(II) Complexes

Two pairs of new mononuclear Schiff base zinc(II) complexes [ZnBr₂(DEDA)] (1) and [ZnBrN₃(DEDA)] (2), [ZnBr₂(IPDA)] (3) and [Zn(NCS)₂(IPDA)] (4) (DEDA=N,N‐diethyl‐N′‐(1‐pyridylmethylidene)ethane‐1,2‐diamine; IPDA=N‐isopropyl‐N′‐(1‐pyridylmethylidene)ethane‐1,2‐diamine), have been obtained from the same synthetic procedure, but with different small secondary ligands. The complexes were characterized by elemental analysis and single‐crystal X‐ray diffraction. The Zn atom in each of the complexes is five‐coordinated in a distorted trigonal-bipyramidal configuration by the NNN donor set of the Schiff base ligand (DEDA for (1) and (2), IPDA for (3) and (4)) and by two other ligands, viz. two Br atoms for (1) and (3), one Br and one terminal N atom of an azide anion for (2), two terminal N atoms of two thiocyanate anions for (4). The small groups (azide and thiocyanate anions) used as the secondary ligands in the preparation of the complexes indicating that they have more coordinative probability to the zinc(II) ions than that of the bromic anion.

Keywords:

• Schiff base
• zinc(II) complex
• synthesis
• crystal structure

This work was supported by the Scientific Research Foundation of the Education Office of Liaoning Province (Project No. 2005226).