Three 3D Lanthanide–Organic Frameworks Based on Novel Flexible Multicarboxylates: From ssa to rtl Topologies

Three lanthanide–organic frameworks have been solvothermally synthesized and characterized. Complex 1 {[Pr2(bbda)(OH)2(H2O)6]·12H2O}n (H4bbda = 5,5′-(2,4,6-trimethyl-1,3-phenylene)bis(methylene)bis(oxy)diisophthalic acid) is a 3D porous framework belonging to a 2-nodal net with the ssa topology. The coordinated formate ligand from in situ hydrolyzation of dmf binds metal centers to generate rigid rod-shaped SBUs (secondary building units) in both complexes 2 and 3, [Ln(HCOO)(L1)(dmf)]n (Ln = Er (2), Tm (3), H2L1 = 2,2′-(2,3,5,6-tetramethyl-1,4-phenylene) bis(methylene)bis(sulfanediyl)dibenzoic acid, dmf = N,N′-dimethylformamide). The flexible ligand H4bbda in complex 1 exhibits syn conformation, while the flexible ligand H2L1 in complexes 2 and 3 adopts anti conformation. The anti L1 ligand links the rod-shaped SBUs to give 2 and 3 3D network with the rtl topology.