Construction of Lanthanide Metal−Organic Frameworks by Flexible Aliphatic Dicarboxylate Ligands Plus a Rigid m-Phthalic Acid Ligand

Six rare earth coordination polymers, namely, [La 2 (H 2 O) 4 (Hip) 2 (L1) 2 ]·4H 2 O ( 1 ) (H 2 L1 = succinate acid, H 2 ip = m -phthalic acid), Ln(H 2 O)(ip) 0.5 (L2) (Ln = Gd ( 2 ), Dy ( 3 ), Y ( 4 ), H 2 L2 = glutaric acid), [Sm 2 (H 2 O) 2 (ip)(L2) 2 ]·3H 2 O ( 5 ), and Er(H 2 O) 2 (ip)(L3) 0.5 ( 6 ) (H 2 L3 = adipic acid), have been synthesized hydrothermally from the self-assembly of the earth ions (Ln 3+ ) with flexible aliphatic dicarboxylate ligands (H 2 L1, H 2 L2, H 2 L3) and the rigid m -phthalic acid ligand (H 2 ip). Compounds 2, 3, and 4 show the common α-Po nets built on six-connected dinuclear Ln 2 units (Ln 2 = Gd 2, Dy 2, and Y 2 ). The structure of compound 5 can be viewed from the tetrahedral sra -nets based on Sm−O−C rods. In compounds 1 and 6, the La−O−C rods and Er−O−C rods are in turn linked by organic spacers to give two dimensional (2D) square nets, which can be further extended to three-dimensional (3D) supramolecular frameworks via hydrogen-bonding contacts. Furthermore, the thermogravimetric analyses of all the compounds were carried out.