Luminescent Mn-based metal-organic framework as an unusual detector to OH- and a multi-responsive sensor for Fe3+, Cr2O72- and CrO42- in aqueous media

Three new LMOFs titled, [Mn(TIPA)(ndc)(H2O)](n) (LMOF-1), [Mn2Cl2(TIPA)(2)(oba)]n (LMOF-2), [Mn3O(TIPA)(oba)3]n (LMOF-3) (TIPA = tris(4-(1H-imidazole-1-yl)phenyl)amine, ndc = 1,4-naphthalene dicarboxylic acid, oba = 4,4'-oxydibenzoic acid) have been synthesized under solvothermal conditions. Single crystal diffraction analysis showed that LMOFs 1-3 were two-node network structures. LMOF-3 had a 2-fold interpenetrating 3D framework made up of pentahedron SBU with Mn3O(CO2)(6) units as the core (The Mn3O(CO2)(6) unit is defined as a pentahedral SBU). LMOF-1 and LMOF-2 on the other hand consist of six-coordinated octahedral structures with a single Mn atom as the core, with an uncoordinated carboxylate group in LMOF-1, selectively detecting Fe3+, CrO(4)(2-)and Cr(2)O7(2)- ions with high quenching constants and low detection limits of 14,647 M -1 and 2.505 x 10(-5) M for Fe3+, 10,705 M-1 and 2.835 x 10(-5) M for CrO4 2-, 6101 M -1 and 3.108 x 10 -5 M for Cr(2)O7(2)& nbsp;(-). It is worth noting that the LMOF-1 exhibited excellent sensing performance for OH-& nbsp;(C) 2022 Elsevier B.V. All rights reserved.