Self-assembly of two 3D microporous coordination polymers based on 2-oxynicotinate and oxalate ligands

Abstract Two new 4f coordination polymers, [ Ln 3 ·(onic) 2 ·(ox) 4 ·(H 2 O) 2 ] · 4H 2 O( Ln  = Yb(1), Tm (2), onic = 2-oxynicotinate, ox = oxalate) have been synthesized and characterized by element analysis, IR spectroscopy and thermal analysis, as well as single crystal X-ray diffraction. Complexes 1 and 2 crystallize in the monoclinic system, space group C2/c, which exhibit the network topology with schlafli symbol of (4.6 4 .4) 2 (4 2 .6 2 .8 2 ) constructed from Ln 2 (ox) units and onic ligands. Moreover, the two complexes represent the 3D microporous coordination frameworks with 25.7% and 24.1% voids occupied by guest water molecules, respectively.