Fabrication of a novel Eu3+-functionalized Mn-MOF based on the X-type tetracarboxylate ligand for efficient temperature sensing

• A novel Mn-organic framework with an X-type tetracarboxylate ligand was obtained. • The Eu@Mn-MOF was successfully constructed by post-synthetic modification strategy. • The Eu@Mn-MOF exhibits good temperature sensing in the wide temperature range. In this work, by utilizing an X-type tetracarboxylate ligand (1,2,4,5-tetrakis(4-carboxyphenyl)benzene, H 4 TCPB), a novel Mn-organic framework, namely, [(CH 3 CH 2 ) 2 NH 2 ] 2 [Mn(TCPB)(H 2 O) 2 ] ( SQNU-25 , SQNU = Shangqiu Normal University), was prepared under a DEF/HAc solm. Due to the structural advantage of SQNU-25 , the Ln 3+ ions (Eu 3+ and Gd 3+ ) have been successfully introduced into the framework by post-synthetic modification. The result of the energy levels of the H 4 TCPB ligand and Eu 3+ ion shows that the H 4 TCPB ligand as a chromophore can effectively sensitize Eu 3+ ions. Moreover, the Eu@SQNU-25 not only shows a typical Eu 3+ ion red emission but also exhibits good temperature sensing in the wide temperature range (80 to 300 K).