The tunable coordination architectures of a flexible multicarboxylate N-(4-carboxyphenyl)iminodiacetic acid via different metal ions, pH values and auxiliary ligand

{[Pb-3(CPIDA)(2)(H2O)(3)] center dot H2O}(n) 1, {[Cd-3(CPIDA)(2)(H2O)(4)] center dot 5H(2)O}(n) 2. [Cd(HCPIDA)(bpy)(H2O)](n) 3 (bpy = 4,4'-bipyridine) and {[Co-3(CPIDA)(2)(bpy)(3)(H2O)(4)] center dot 2H(2)O), 4 were synthesized with N-(4-carboxyphenyl) iminodiacetic acid (H(3)CPIDA). In 1, the CPIDA(3-) ligands adopt chelating and bridging modes with Pb(II) to possess a 3D porous framework. In 2D-layer 2, the CPIDA(3-) ligands display a simple bridging mode with Cd(II). The 2D layers have parallelogram-shaped channels along a axis. With bpy ligands, the HCPIDA(2-) ligands in 3 show more abundant modes, but 3 still displays a 2D sheet on bc plane for the unidentate bpy molecules. However, in 3D-framework 4, the bpy ligands adopt bridging bidentate at a higher pH value and the CPIDA(3-) ligands show bis-bidentate modes with Co(II). Additionally, 2D correlation analysis of FTIR was introduced to ascertain the characteristic adsorptions location of the carboxylate groups with different coordination modes in 4 with thermal and magnetic perturbation. Compounds 1, 2 and 4 exhibit the fluorescent emissions at room temperature. (C) 2009 Elsevier Inc. All rights reserved.