Syntheses and Crystal Structures of Two Acetato-Bridged Trinuclear Zinc(II) Complexes Derived from 4-Chloro-2-[(2-ethylaminoethylimino)methyl]phenol and 4-Chloro-2-[(2-isopropylaminoethylimino)methyl]phenol

Abstract

The reaction between zinc(II) acetate with the similar tridentate Schiff bases 4-chloro-2-[(2-ethylaminoethylimino) methyl]phenol (HL1) and 4-chloro-2-[(2-isopropylaminoethylimino)methyl]phenol (HL2), produces two trinuclear zinc(II) complexes, [Zn{Zn(L1)(μ₂-acetato-O,O)(μ₂-acetato-O,O′)}₂] (1), and [ZnZn(L2)(μ ₂ -acetato-O,O)(μ₂-acetato-O,O′)₂] (2), in which two deprotonated Schiff base ligands are coordinate to three zinc(II) atoms, one hexa- and the other two penta-coordinate via the phenolic oxygen, imine nitrogen and amine nitrogen atoms. The coordination spheres of the zinc atoms being completed by acetate oxygen atoms. Two of the acetate groups bridge adjacent two zinc atoms via single oxygen atoms, while the other two bridge adjacent two zinc atoms via both oxygen atoms. In each of the complexes, the central Zn atom is located on an inversion center and has an octahedral coordination. The coordination around the terminal Zn atoms may be regarded as midway between trigonal-bipyramidal and square-pyramidal. The Zn…Zn distances are 3.060(2) Å in (1), and 3.059(2) Å in (2), respectively.

Keywords:

• crystal structure
• Schiff base
• synthesis
• zinc complex

Notes

^a R ₁ = ∑ ‖ F _o | – | F _c ‖/∑ | F _o |, wR ₂ = [∑ w(F _o ² – F _c ²)²/∑ w(F _o ²)²]^1/2, w ₍₁₎ = [σ²(F _o )² + (0.0496 (F _o ² + 2F _c ²)/3)² + 1.6360(F _o ² + 2F _c ²)/3]^–1, w ₍₂₎ = [σ²(F _o )² + (0.0207(F _o ² + 2F _c ²)/3)² + 0.7206(F _o ² + 2F _c ²)/3]^–1.