Crystal structure of catena-poly[[[trans-bis(acetonitrile-κN)diaquacobalt(II)]-μ-pyrazine-κ2N:N′] dinitrate]

Abstract

The central structural motif of the title coordination polymer, [Co(NO3)2(C4H4N2)(CH3CN)2(H2O)2]n, is a chain composed of CoII ions linked by bis-monodentate bridging pyrazine ligands through their N atoms. The CoII ion is located on an inversion center and is additionally coordinated by two O atoms of water molecules and two N atoms of acetonitrile molecules. The resultant N4O2 coordination sphere is distorted octahedral. The linear cationic chains extend parallel to the a axis and are aligned into layers parallel to the ac plane. Nitrate anions are situated in the space between the CoII chains and form O—H...O hydrogen bonds with the coordinating water molecules, leading to a three-dimensional network structure. Weak C—H...O hydrogen bonds are also present between pyrazine or acetonitrile molecules and the nitrate anions.

Keywords

• crystal structure
• one dimensional coordination polymer
• cobalt(II) complex
• pyrazine ligand
• acetonitrile ligand