Syntheses, Characterization, and Crystal Structures of Bromido-Coordinated Zinc(II) Complexes With Multidentate Schiff Bases

Abstract

A new dinuclear bromido-coordinated Schiff base zinc(II) complex, [Zn₂Br₂L¹(MeOH)]·MeOH (1), and a new mononuclear bromido-coordinated Schiff base zinc(II) complex, [ZnBr₂L²] (2), where L¹ is the dianionic form of N,N’-bis(5-fluoro-2-hydroxybenzylidene)propane-1,3-diamine (H₂L¹), and L² is the zwitterionic form of 2-[(3-dimethylammoniopropylimino)methyl]-4-fluorophenol, have been preprared and characterized mainly by single-crystal X-ray diffraction. Complex 1 crystallizes in the monoclinic space group P2₁/n with unit cell dimensions a = 10.0876(9) Å, b = 8.9549(8) Å, c = 26.586(2) Å, β = 95.134(2)º, V = 2391.9(4) Ǻ³, Z = 4, R₁ = 0.0547, and wR₂ = 0.1025. Complex 2 crystallizes in the monoclinic space group P2₁/c with unit cell dimensions a = 7.359(1) Å, b = 13.798(2) Å, c = 17.676(2) Å, β = 114.602(2)º, V = 1631.8(4) Ǻ³, Z = 4, R₁ = 0.0877, and wR₂ = 0.2197. The inner Zn atom in 1 is five-coordinated in a square pyramidal geometry. The outer Zn atom in 1 and the Zn atom in 2 are four-coordinated in tetrahedral geometry. The crystals of the complexes are stabilized by intermolecular hydrogen bonds.

Keywords:

• Schiff base
• zinc(II) complex
• crystal structure
• hydrogen bonds