Four 3D coordination polymers based on layers with single - carboxylate bridges: synthesis, structures, and magnetic properties.

Four novel coordination polymers (CPs) based on a new 4-(3,5-dicarboxylphenyl) picolinic acid ligands (HL), [M(L)(HO)]·4HO (M = Mn, 1; Co, 2; Ni, 3, CoNi, 4), have been hydrothermally synthesized, and structurally and magnetically characterized. In these isomorphous CPs, octahedrally coordinated metal ions are linked by the single - carboxylate bridge (μ-COO) to give linear trinuclear motifs. The motifs are connected through the other single - carboxylate bridge (μ-COO) to give a 2D (4,4) layer, and the layers are interlinked by the L ligands into 3D frameworks.

2D carboxylate-bridged Ln coordination polymers: displaying slow magnetic relaxation and luminescence properties in the detection of Fe, CrO and nitrobenzene.

Eight new 2D isostructural lanthanide coordination polymers (Ln-CPs), [Ln(HL)(HO)(NO)]·NO (1-Ln), Ln = Nd, Sm, Eu, Gd, Tb, Dy, Ho, and Yb ions, HL = 4-(3,5-dicarboxylphenyl)-2-methylpyridine, were synthesized by using solvothermal methods and studied by structural analyses, magnetic analyses and luminescent probes. Crystallographic studies revealed that these compounds are 2D frameworks in which dinuclear units with double μ-syn,syn-carboxylate bridges are interlinked by single μ-trans,trans-carboxylate bridges from organic spacers. The layers are further stabilized and combined into 3D architectures through intra- and interlayer ππ stacking interactions and hydrogen bonding, respectively.