Synthesis, crystal structure, and magnetic properties of a new onedimensional chain antiferromagnet Co(ox)(bib)?H₂O (ox = oxalate; bib=1,4-bis(imidazole-1-yl)benzene)

A new one-dimensional (1D) chain antiferromagnet Co(ox)(bib)center dot H2O 1 (ox = oxalate; bib = 1,4-bis(imidazole-1-yl)benzene) has been successfully synthesized under hydrothermal condition and characterized by single crystal X-ray crystallography, powder Xray diffraction, thermogravimetric analysis, Fourier transform infrared (FTIR) spectroscopy, magnetic susceptibility, and heat capacity measurements. The Co-II ion is connected by oxalate ions in trans -configuration to form 1D Co-II-ox-Co-II spin chains, which are further separated by the long organic molecule bib. The magnetic susceptibility curve shows that 1 exhibits a feature of broad maximum around 29 K, indicating strong antiferromagnetic interactions with short spin -spin correlations along the spin chains. However, no long-range order is observed due to the negligible interchain interactions through bib ligand and weak hydrogen bonds, which is further confirmed by the heat capacity data. The intrachain interaction J of -8.4 K is estimated. Both magnetic susceptibility and heat capacity results indicate that 1 exhibits a good 1D magnetism.