Two unique M-MOFs (M:Zn, Mn) based on various metal-oxygen chains for good sensitivity sensing and magnetic properties

In this paper, two novel two-dimensional MOFs were synthesized by solvothermal reaction of 2,4-di(2 & PRIME;,5 & PRIME;- dicarboxylphenyl)benzoic acid ligand and Zn(II) and Mn(II) metal ions: {[Zn2(HL)(H2O)(DMF)2]& BULL;(H2O)& BULL;(DMF)}n (1), {[Mn2(HL)(H2O)(DMF)2]& BULL;(H2O)& BULL;(DMF)}n (2). Complexes 1 and 2 are unique two-dimensional skeletons with particular metal-oxygen chains in their structures. The solid-state luminescence spectrum of complex 1 shows that its maximum emission peak is 448 nm. Further fluorescence studies of complex 1 show that it can efficiently detect Fe3+ and Cr2O72-in aqueous solution with a detection limit of 4.1 x 10-4 M and 2.7 x 10-4 M respec-tively, and has good recycling performance, so it is a potential bifunctional fluorescent probe material. The mechanism of fluorescence sensing quenching was also investigated in detail. Furthermore, magnetic studies have shown that there is an antiferromagnetic interaction between Mn(II) ions of complex 2.