Syntheses, Structures And Properties Of Complexes With Polyhalogen Substituted Benzenedicarboxylate Ligands

On the basis of construction strategy of crystal engineering, a variety of halogen substituted aromatic carboxylic acids and its Schiff bases derivatives were chosen as the building blocks to assembly with metal ions to afford novel topological metallosupramolecular complexes. The keys point of this research are on the emphasis of synthetic methodology of interesting metallosupramolecular complexes, directional regulation of binding fashion from substituents to ligand, analysis of assembly discipline of topological network, and impact of co-ligand to the resultant framework.As a good participant for cocrystallization, tetrachloroterephthalic acid (H2BDC-Cl4) was synthesized and used to the formation of cocrystals with 4,4'-bipyridine and 1,10-phenanthroline. Compound 1 and 2 were yield successfully with structural determination on the basis of tetrachloroterephthalic acid, which offer important structural information to the study of related coordination complexes and enrich the supramolecular chemistry on other halogen substituted analogue.When reacting with different metal ions, such as Cuâ…¡, Znâ…¡, Mnâ…¡, Pbâ…¡centers, (H2BDC-Cl4) units fulfill seven coordination polymers (3-9) varing from one-dimensional double chains, two-dimensional grid, to three-dimensional sra, pts and tetranuclear pcu networks. The reactions of Znâ…¡salts and H2BDC-Cl4 in the condition of co-ligand 2,2'-bipyridine and 1,10-phenanthroline give two Znâ…¡complexes (10-11) with distinct coordination geometries. Significantly, solvent system plays a key role in the templating and structural directing of the assemblies of Cuâ…¡polymers.To further exploit the structural diversification with halogen substituted benzenedicarboxylate, tetrafluoroterephthalic acid (H2BDC-F4) were utilized to assemble with Znâ…¡and Pbâ…¡salts, resulting in one-dimensional chain-motif and three-dimensional rod-packing coordination polymers 12-14. For the Pbâ…¡-containing complexes, the final coordination networks are independent to solvent effects but rely on the geometries of rigid ligands. Tetrafluorophthalic acid were first applied to the construction coordination polymers with Cdâ…¡salts, yielding one double-chain motif polymer of 15 and two-dimensional framework of 16. The judicious choice of solvent systems does play a critical role in the construction of coordination frameworks with distinct dimensionality and connectivity.N,N'-Bis(2-pyridinylmethylene)-2,3,5,6-tetrafluoro-1,4-benzenedimethanamine (L1) and its analogues (L2-L6) were synthesized for the first time and initialized to the preparation of three unique one-dimensional coordination polymers 20-22 on the basis Znâ…¡or Cdâ…¡ions in the existence of oxalates through hydrothermal technology. When the co-ligand was replaced by tetrafluorophthalate, the reaction of L1 and Mnâ…¡ions in ambient provides coordination polymer 23 with two-dimensional framework. Compounds 20,21, and 23 all exhibit helical motif, which offer important structural information for further studies on non-linear hybrid materials.