Magnetic study of a one-dimensional Mn(II) coordination polymer dealing with π–π stacking

✍ Scribed by Jing-Min Shi; Xian-Zhe Meng; You-Min Sun; Hai-Yan Xu; Wei Shi; Peng Cheng; Lian-Dong Liu

• Publisher: Elsevier Science
• Year: 2009
• Tongue: English
• Weight: 675 KB
• Volume: 917
• Category: Article
• ISSN: 0022-2860
• DOI: 10.1016/j.molstruc.2008.07.011

✦ Synopsis

A new one-dimensional chain manganese(II) coordination polymer, {[Mn(l-Dpd)(Q) 2 (H 2 O) 2 ]2(ClO 4 )} n (Dpd = 2,5-dimethylpyrazine-1,4-dioxide; Q = 8-hydroxylquinoline N-oxide), was synthesized with 2,5dimethylpyrazine-1,4-dioxide as bridge ligand and 8-hydroxylquinoline N-oxide as terminal ligand, and its crystal structure determined by X-ray crystallography. The structure analysis indicates that there are two pathways for magnetic interactions: one is through bridge ligand 2,5-dimethylpyrazine-1,4-dioxide, and another is by p-p stacking of adjacent quinoline rings. The theoretical calculations reveal that there exist a anti-ferromagnetic interaction from spin delocalization and a ferromagnetic interaction from spin polarization for 2,5-dimethylpyrazine-1,4-dioxide bridge pathway, but the anti-ferromagnetic interaction is stronger than the ferromagnetic interaction, leading to an anti-ferromagnetic interaction with J = À2.53 cm À1 ; whereas for the p-p stacking pathway it resulted in a ferromagnetic interaction with J = 0.013 cm À1 . The experimental fitting on the data of the variable temperature magnetic susceptibilities gave the magnetic interaction constant J = 0.07 cm À1 , which is similar with the results of the theoretical calculations.