To Build A Flexible Imidazole-based Ligands Synthesis, Structure And Nature Of The Study

Coordination polymers constructed by flexible ligand has attracted the attention of the Chemists, becoming one of the hotspot in inorganic chemistry. Not only because of its flexibility in changing the topology and also owing to its potential applications in the optical, electrical magnetic, separation, catalysis, gas storage. The appropriate ligands were synthesized, crystal engineering principles were used for design of the special structure and assembly of coordination polymers, which is proved as an effective means to build coordination polymers. In this paper, we designed and synthesized a flexible ligand--1,4-bis(2-methyl-imidazol-1-yl) butane, and allocated organic acids, inorganic salts to react under different conditions. Finally, ten coordination polymers containing flexible bisimidazole ligands were successfully synthesized under the guidance of the principle of crystal engineering.{[Zn(bib)(male)]2-2H2O}n (1),{[Zn(bib)(fum)]·CH3OH}n (2),{[Zn(bib) (suc)]·H2O}n (3),{[Zn(bib)(bpdc)]·2H2O}n (4),{Cd(bib)Cl2}n (5),{[Cd(bib)(oba)]·2H2O}n (6),{[(H2bib)SnCl6]·H2O}n (7),{[Co(bib)(m-bdc)]}n (8),{[Co(bib)(oba)]}n (9),{[Cu(bib) (w-bdc)]4·5H2O}n (10) (bib= 1,4-bis(2-methyl-imidazol-1-yl)butane, H2mal= maleic acid, H2fum= fumaric acid, H2suc= succinic acid, H2oba= 4,4'-oxybis(benzoate), H2bpdc= 2,2'-bipyridine-3,3'-dicarboxylate, m-H2bdc= m-phthalic acid), Complex 1 and 3 present 2D wave-like layerc structures, and the layers are connected through van der Waals forces and hydrogen bonds into 3D supramolecular structures, respectively. Complex 2 and 4 exhibit 3D interpenetrating diamondoid networks. Compound 5 exhibits two kinds of infinite 1D chain structures, They are perpendicular to each other, and the adjacent chains are connected through hydrogen bonds into 3D supramolecular structures. Complex 6 exhibits 3D five-fold interpenetrating diamondoid networks. Complex 7 is the organic-inorganic tin compound. This compound exhibits three dimensional layer struetures for the presence of inter-and intramolecular weak hydrogen bonds. Complex 8 exhibits 3D three-fold interpenetrating networks. Bib and oba ligand bridging metal ions form a 2D wave-like layer structure in complex 9, in the generation of 3D assemblies by parallel interpenetration, these planes of the nets are parallel but not coincident. Complex 10 presents four-connected self-penetrating networks.