Studies on synthesis, optical and magnetic properties of Zn, Mn, Co and Ni complexes of biphenylenedicarboxylic acid ligands

In order to further enrich the research on the synthesis of complexes with multi carboxyl ligands and transition metals. In this study, [1,1′-biphenyl]-2,4′-dicarboxylic acid ligand (H2bpda), 2,2′-dipyridyl (2,2′-dipy) and 4,4′-dipyridyl (4,4′-dipy) were used to construct metal complexes with Zn2+, Mn2+, Co2+and Ni2+by solvothermal reaction, and seven complexes were constructed, namely, [Zn(Hbpda)2 (4,4′-dipy)2] (1), [Mn(Hbpda)2(4,4′-dipy)2•(4,4′-dipy)]n (2), [Co(Hbpda)2(4,4′-dipy)2] (3), [Ni(bpda)(4,4′-dipy)1.5 •4H2O]n (4), [Mn(bpda)(2,2′-dipy)]n (5), [Co(bpda)(2,2′-dipy) •2H2O]n (6) and [Ni(bpda)(2,2′-dipy) •2H2O]n (7); Single crystal x-ray diffraction analyses reveal that complexes 1 and 3 have zero-dimensional mononuclear structure, 2, 4 and 5 have one-dimensional chain structure, 6 and 7 have two-dimensional network structure. Furthermore, solid state fluorescence properties of complexes 1–7 and magnetic properties of complexes 2, 3, 4, 5, 6 and 7 were investigated. The fluorescent test results show that complex 1 has excellent fluorescence performance and the fluorescence intensity is higher than that of ligand; The magnetic results indicate that complexes 2, 4 and 7 have ferromagentic property and complexes 3, 5 and 6 have antiferromagentic property.