A novel pillar-layered Mn–organic framework constructed from 1D S-shaped chains and flexible tricarboxylate ligands for wide-range temperature sensing

In this work, by using a flexible tricarboxylate ligand 5-(4-carboxybenzyloxy) isophthalic acid (H₃L), a novel pillar-layered Mn–organic framework, namely, [(CH₃CH₂)₂NH₂][Mn₃(HL)L(A_C)₂] (SQNU-23, SQNU = Shangqiu Normal University), was synthesized by using a DEF/HAc solvent system. In SQNU-23, each S-shaped Mn-O chain is interconnected by two bridging modes of organic ligand to form a 3D pillar-layered framework with 1D rectangular channels. The solid-state fluorescence of SQNU-23 exhibits a significant red shift of about 140 nm compared to that of organic ligand. Moreover, SQNU-23 as a luminescent thermometer exhibits good linear dependence in the wide temperature range (100 to 300 K).