Synthesis and Characterization of Cobalt(II), Nickel(II), and Zinc(II) Complexes with N,N′‐bis(2‐nitrocinnamaldehyde)‐1,2‐diiminoethane Ligand. Crystal Structure of Zn(nca₂en)Br₂

S.D. would like to acknowledge the Islamic Azad University Research Council for partial support of this work.

A series of complexes of the type M(nca₂en)X₂, where nca₂en=/N,N′‐bis(2‐nitrocinnamaldehyde)‐1,2‐diiminoethane, M(II) =Co, Ni or Zn and X=Cl, Br, I have been synthesized and characterized. The crystal and molecular structure of Zn(nca₂en)Br₂ 8 was determined by X‐ray crystallography from single‐crystal data. The complex 8 crystallizes in monoclinic system, having Zn ion in distorted tetrahedral geometry, Br(1)‐Zn(1)‐ Br(2), 117.37(4)°; N(3)‐Zn(1)‐N(2), 82.57(18)°. This structure consists of intermolecular hydrogen bond of the type C‐H‐X. The formation of the C‐H‐M weak intramolecular hydrogen bonds due to the trapping of C‐H bonds in the vicinity of the metal atoms is reported for 8. The ¹H NMR study of Zn complexes gives further evidence for the presence of such interactions. The spectral properties of the above complexes are also discussed.

Keywords:

• Schiff base complexes
• cobalt(II)
• nickel(II)
• zinc(II)
• tetrahedral
• crystal structures
• nitrocinnamaldehyde

Notes

S.D. would like to acknowledge the Islamic Azad University Research Council for partial support of this work.