Lanthanide-tricarboxylate frameworks: Synthesis, structure and photoluminescence property

Abstract Reactions of tricarboxylate ligands biphenyl-3,4′,5-tricarboxylic acid (H 3 L 1 ) and [1,1′:3′,1″-terphenyl]-4,4″,5′-tricarboxylic acid (H 3 L 2 ) with the lanthanide metal salts under solvothermal conditions give rise to five new lanthanide-organic frameworks. Complexes {[Ln(L 1 )(H 2 O)(DMF)]·DMF·H 2 O} n [Ln = La ( 1 ), Ce ( 2 ) and Sm ( 3 )] with (L 1 ) 3− have the same framework structures, while the frameworks based on the ligand (L 2 ) 3− with formula {[Ln(L 2 )(H 2 O) 2 ]·2DMF·14H 2 O} n [Ln = Sm ( 4 ) and Gd ( 5 )] are also isostructural. All the complexes have binuclear paddlewheel [Ln 2 (CO 2 ) 4 ] clusters as the secondary building units, which are further linked together by the organic ligands to form three-dimensional (3,6)-connected frameworks. In addition, thermal stability and photoluminescence properties of 1 – 5 were investigated.