Synthesis and Structure of a Bipyridyldicarboxylate Connected Neodyminum Organic Framework

The porous neodymium coordination polymer {L₃Nd₂(H₂O)₄] (LH₂ = 2,2′‐bipyridine‐5,5′‐dicarboxylic acid)} ( 1 ) was prepared via a hydrothermal synthesis approach starting from Nd(NO₃)₃·6H₂O and 2,2′‐bipyridine‐5,5′‐dicarboxylic acid in a one to one mixture of ethanol and water at 160°C. The product was characterized by single crystal X‐ray diffraction, TGA and elemental analysis. Space group: P , a: 6.0294(4), b: 10.9061(6), c: 13.8392(9) Å, α: 101.486(7), β: 93.799(8)°, γ: 100.933(7)°, R1 > 2σ (I)] = 0.0147, wR2 (all data) = 0.0328. The structure determination revealed 1 to be a 3‐dimensional network with eight‐coordinated lanthanide centres acting as 5‐connectors and two types of bipyridyldicarboxylate cross‐linkers, as 3‐ and a 4‐connectors. After the loss of water – two per neodymium atom‐channels are formed with a channel diameter of 4.82 Å atom to atom distances (Nd‐O)].