Synthesis, structure, fluorescence, and magnetic studies of a series of transition metal complexes with oxygen-bridged phenylene tricarboxylic acid ligand

In this work, 4-(2-carboxyphenoxy)phthalic acid ligand (H 3 bppa), 4,4′-dipyridyl (4,4′-dipy), 1,10-phenanthroline (phen), 2,2′-dipyridyl (2,2′-dipy) and transition metal ions Zn 2+ , Cu 2+ , Mn 2+ , Ni 2+ , Co 2+ were used to synthesize metal complexes by solvothermal reaction. Ten complexes were synthesized, namely, [Zn(H 2 bppa) 2 (H 2 O) 4 ]·4H 2 O ( 1 ), [Mn(H 2 bppa) 2 (H 2 O) 4 ]·4H 2 O ( 2 ), [Co(H 2 bppa) 2 (H 2 O) 4 ]·4H 2 O ( 3 ), [Mn(H 2 bppa) 2 (2,2′-dipy) (H 2 O)] n ( 4 ), [Cu(H 2 bppa) 2 (2,2′-dipy) (H 2 O)] n ( 5 ), [Mn 3 (bppa) 2 (4,4′-dipy) 2 (H 2 O) 6 ] n ( 6 ), [Co(Hbppa) (phen) 2 (H 2 O)] ( 7 ) and [Ni(Hbppa) (phen) 2 (H 2 O)] ( 8 ), [Mn(Hbppa) (phen) (H 2 O)] n ( 9 ), [Cu(Hbppa) (phen) (H 2 O)] n ( 10 ). Structural datas were collected by X-ray single crystal diffractometer, the results show that complexes 1, 2, 3, 7 and 8 are zero-dimensional mononuclear structure, 4, 5, 9 and 10 are one-dimensional chain structure, 6 is three-dimensional network structure. Furthermore, solid state fluorescence properties were performed on complexes H 3 bppa and 1 – 8 , magnetic properties were performed on complexes 2 – 8 . The fluorescence experiment results show that the fluorescence intensity of complexes 1 – 8 is weaker than that of H 3 bppa, and the fluorescence emission spectrum of complex 1 undergoes a blue shift relative to the H 3 bppa. Magnetic testing data analysis shows that complexes 2, 3 and 8 have antiferromagentic properties and complexes 4, 5, 6 and 7 have ferromagentic properties.