Pyrazolato-bridged 1-D Co(II) coordination polymer and dinuclear Ni(II) and Cu(II) complexes: Syntheses, crystal structures and magnetic properties

• Published in: Inorganica Chimica Acta 2009-05, Vol.362 (7), p.2247-2252
• Main Authors: Zhang, Su-Yun, Li, Yahong, Li, Wu
• Format: Article
• Language: English
• Subjects: 1-D chain complex; Dinuclear complexes; Magnetic properties; Structures; Syntheses
• ISSN: 0020-1693; 1873-3255
• DOI: 10.1016/j.ica.2008.10.010

Three complexes of composition [Co 3(Hdcp) 2(phen) 3(H 2O) 2] n · nH 2O ( 1), [Ni 2(Hdcp) 2(H 2O) 4](Im) 2 ( 2) and [Cu 2(Hpca) 2(H 2O) 2(Im) 2] ( 3) have been synthesized via hydrothermal reactions and their structures have been characterized. Complex 1 exhibits one-dimensional linear chain structure. Complexes 2 and 3 are pyrazolato-bridged dinuclear complexes. The results of magnetic susceptibility measurements indicate that there exist antiferromagnetic interactions between Co(II) and Ni(II) centres in compounds 1 and 2, respectively. Three complexes of composition [Co 3(Hdcp) 2(phen) 3(H 2O) 2] n · nH 2O ( 1), [Ni 2(Hdcp) 2(H 2O) 4](Im) 2 ( 2) and [Cu 2(Hpca) 2(H 2O) 2(Im) 2] ( 3) (H 3dcp = 3,5-pyrazoledicarboxylic acid, H 2pca = 1 H-pyrazole-5-carboxylic acid, Im = imidazole and phen = 1,10-phenanthroline) have been synthesized via hydrothermal reactions and their structures have been characterized. Complex 1 is mainly constructed by Hdcp and ancillary ligand 1,10-phenanthroline and exhibits one-dimensional linear chain structure. Complexes 2 and 3 are pyrazolato-bridged dinuclear complexes. The ancillary imidazole ligand was not involved in the coordination and stacked to the lattice of the complex in 2. In the process of synthesis 3, imidazole ligand was coordinated to the metal centre; with one of the carboxylic group of the H 3dcp ligand was eliminated to form [Cu 2(Hpca) 2(H 2O) 2(Im) 2] ( 3) in situ. The results of magnetic susceptibility measurements indicate that there exist antiferromagnetic interactions between Co(II) and Ni(II) centres in compounds 1 and 2, respectively.