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)(.)6H(2)O and 2,2'-bipyridine-5,5'-dicarboxylic acid in a one to one mixture of ethanol and water at 160degreesC. The product was characterized by single crystal X-ray diffraction, TGA and elemental analysis. Space group: P (1) over bar, a: 6.0294(4), b: 10.9061(6), c: 13.8392(9) Angstrom, alpha: 101.486(7), beta: 93.799(8)degrees, gamma: 100.933(7)degrees, R1 [> 2sigma (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 Angstrom [atom to atom distances (Nd-O)].