Significant positional isomeric effect of zwitterionic ligands on the construction of two different 2D and 3D Pb(II) coordination polymers

• Distinct coordination polymers can be obtained from PbII and two positional isomers.
• Ligands are 1-carboxylatomethylpyridinium-3-carboxylate and 4-carboxylate analogue.
• Structural divergences are due to the positional isomeric effect of ligands.
• Two novel 2D and 3D topological networks are generated.

Hydrothermal reactions of PbCl2 with two positional isomers of asymmetric zwitterionic ligands 1-carboxylatomethylpyridinium-3-carboxylate (HL3) and 1-carboxylatomethyl-pyridinium-4-carboxylate (HL4) result in the formation of two coordination polymers (CPs) [Pb(L3)Cl] (1) and [Pb1.5(L4)2Cl(H2O)] (2), respectively. CPs 1 and 2 were characterized by elemental analysis, IR, powder X-ray diffraction, and single-crystal X-ray diffraction. 1 and 2 exhibit the 2D (4,4)-connected and 3D (3,4,4,5)-connected novel topological networks with (43.62.8) and (42.124)(42.6)2(43.6.84.102)2(46)2 point symbols, respectively, which reveal the significant positional isomeric effect of the zwitterionic ligands on the construction of CPs. Their thermal and photoluminescent properties were also investigated.

Two Pb(II) coordination polymers [Pb(L3)Cl] (1) and [Pb1.5(L4)2Cl(H2O)] (2) were assembled from the hydrothermal reactions of PbCl2 with a pair of positional isomers 1-carboxylatomethylpyridinium-3-carboxylate (HL3) and 1-carboxylatomethyl-pyridinium-4-carboxylate (HL4), which show the novel 2D (4,4)-connected (43.62.8) and 3D (3,4,4,5)-connected (42.124)(42.6)2(43.6.84.102)2(46)2 coordination networks, respectively.Figure optionsDownload as PowerPoint slide