Piperazinium hexaaquacobalt(II) bis[bis(pyridine-2,6-dicarboxylato)cobaltate(II)] octahydrate

✍ Scribed by Aghabozorg, Hossein ;Attar Gharamaleki, Jafar ;Ghadermazi, Mohammad ;Ghasemikhah, Pouya ;Soleimannejad, Janet

• Publisher: International Union of Crystallography
• Year: 2007
• Tongue: English
• Weight: 530 KB
• Volume: 63
• Category: Article
• ISSN: 1600-5368
• DOI: 10.1107/s1600536807025640

✦ Synopsis

The title compound, (C 4 H 12 N 2 )[Co(H 2 O) 6 ][Co(C 7 H 3 O 4 ) 2 ] 2 Á-8H 2 O, was obtained by the reaction of cobalt(II) nitrate hexahydrate with the proton-transfer compound piperazinediium pyridine-2,6-dicarboxylate or (pipzH 2 )(pydc) (where pipz is piperazine and pydcH 2 is pyridine-2,6-dicarboxylic acid) in aqueous solution. The anionic complex, [Co(pydc) 2 ] 2À , features six-coordinate Co II with a distorted octahedral geometry. The structure also contains hexaaquacobalt(II) cations (site symmetry 1), and piperazinium (site symmetry 1) as counter-ions and eight uncoordinated water molecules. The torsion angles indicate that the (pydc) 2À units are almost perpendicular to each other. In the crystal structure, extensive O-HÁ Á ÁO, N-HÁ Á ÁO and C-HÁ Á ÁO hydrogen bonds, as well as ion pairing and distances forinteractions between anion fragments, play an important role in stabilizing the structure.