Syntheses and Structures of a Pair of Isologous Complexes: ZnLCl₂ and ZnLBr₂

Abstract

A pair of mononuclear Schiff base zinc(II) complexes, [ZnLCl₂] (1) and [ZnLBr₂] (2), have been prepared by the reaction of equimolar quantities of a new Schiff base ligand 2-[(2-dimethylammonioethylimino)methyl]-4-methylphenolate with ZnCl₂ and ZnBr₂, respectively, in methanol. The structures of the complexes have been characterized by single-crystal X-ray diffraction. Complex 1 crystallizes as orthorhombic space group P2₁2₁2₁, with unit cell dimensions a = 7.518(1) Å, b = 13.518(2) Å, c = 14.766(2) Å, V = 1500.7(3) ų, Z = 4, R ₁ = 0.0301, wR ₂ = 0.0780, S = 1.028. Complex 2 crystallizes as orthorhombic space group P2₁2₁2₁, with unit cell dimensions a = 7.731(1) Å, b = 13.761(1) Å, c = 14.705(1) Å, V = 1564.4(1) ų, Z = 4, R ₁ = 0.0230, wR ₂ = 0.0488, S = 1.031. The Zn atom in each of the complexes is four-coordinated in a tetrahedral geometry by the phenolate O and imine N atoms of the Schiff base ligand, and two halide anions. Single crystals of the complexes are stabilized by hydrogen bonds.

Keywords:

• Crystal structure
• hydrogen bonding
• Schiff base
• zinc complex