Studies on the magnetic properties of two cobalt(II) complexes bearing 1,4-phenylenediacetate ligands

• Published in: Transition metal chemistry (Weinheim) 2010-11, Vol.35 (8), p.991-997
• Main Authors: Chen, Zi-Lu, Xiong, Wei, Zhang, Zhong, Liang, Fu-Pei, Luo, Bing-Chang
• Format: Article
• Language: English
• Subjects: Catalysis; Chemistry; Chemistry and Materials Science; Inorganic Chemistry; Organometallic Chemistry; Physical Chemistry
• ISSN: 0340-4285; 1572-901X
• DOI: 10.1007/s11243-010-9421-7

One reported compound [Co(PDA)(4,4′-bipy)] n ·nH 2 O and one new compound [Co(PDA)(Im) 2 (H 2 O) 2 ] n ·nH 2 O were prepared by the reactions of Co(NO 3 ) 2 ·6H 2 O or Co(OH) 2 with 1,4-phenylenediacetic acid (H 2 PDA) in the presence of the ancillary ligands 4,4′-bipyridine (4,4′-bipy) or imidazole (Im), and their magnetic properties were investigated. The presence of 4,4′-bipy in [Co(PDA)(4,4′-bipy)] n ·nH 2 O results in a μ 3 -bridging mode of the PDA 2− ligand with one μ 2 -carboxylato group and one chelating carboxylato group and the construction of a 2D framework as reported in the literature. The introduction of Im ligand in [Co(PDA)(Im) 2 (H 2 O) 2 ] n ·nH 2 O helps to construct a one dimensional chain with the two carboxylato groups of PDA 2− ligand in monodentate coordination modes. The magnetic studies reveal the presence of dominant antiferromagnetic interaction in [Co(PDA)(4,4′-bipy)] n ·nH 2 O with a field-induced magnetic transition due to spin-flop. Magnetically, [Co(PDA)(Im) 2 (H 2 O) 2 ] n ·nH 2 O presents a mononuclear structure. This work reveals that the introduction of ancillary ligands in the Co(II)-PDA system adjusts the linking modes of PDA 2− and therefore the resulting frameworks and their magnetic properties.