Syntheses, Structure And Properties Of Supramolecular Complexes Based On α-Ketoglutaric Acid

The supramolecular complexes were consisit of coordinate bond, hydrogen bond, π···π stack interaction and other weak intermolecular interactions. It is not only with versatile topology, but also have potential applications in many field, such as gas storage, gas separation, luminescence, catalysis, biological activity. Thus, the design and construction of supramolecular complexes are becoming the hot topic of current. In the design of the supramolecular complexes synthesis, organic ligands in the construction of supramolecular network structure plays a key role. The novel structures and properties of supramolecular complexes are systhesized, while features of flexible ligand interpenetrating and twining. In this paper, we adopts the α-ketoglutaric acid, a flexible ligand, to synthesize eleven supramolecular complexes, and analyze the structure with Single x-ray diffraction, elemental analysis, IR, TGA and PXRD.1. Ten crystalline adducts derived from α-ketoglutaric acid and imidazole and its derivatives were prepared under solvothermal conditions.O f the ten comlexes eight are organic salts(1-7 and 10) and the other three(8 and 9) are cocrystals. All ten supramolecular assemblies involve extensive intermolecular classical hydrogen bonds as well as other noncovalent interactions. These noncovalent interactions combined, all the complexes displayed 3D supramolecular structure. The results presented herein indicate that the strength and directionality of the classical O-H···O, and O-H···N hydrogen bonds(ionic or neutral) and other nonbonding associations between α-ketoglutaric and imidazole and its derivatives are suf?cient to bring about the formation of organic salts or cocrystals. When the part of compounds as bacteriostatic agent and its concentration is 25 mg/mL, from obvious bacteriostatic circle we found that its works for escherichia coli and is not worked for the golden yellow staphylococcus.2. Complexe 11 was prepared based on α-ketoglutaric acid, 2,2’-bipyridine with copper acetate under hydrothermal condition by in situ reaction of α-ketoglutaric acid. Single crystal X-Ray diffraction analysis reveals that the ligands of complex 11 are oxalate and 2,2’-bipyridine. Oxalate and malonic acid are in situ decomposition of α-ketoglutaric acid. The complex 11 moleculars connected each other by the hydrogen bonding and π···π stacking interactions to give a three dimensional supramolecular structure. The complex 11 was applied to the epoxidation of styrene reaction, and the catalytic results show that the complex catalyst possesses 47.2% styrene conversation and 43.6% selectivity of epoxyethylbenzene at 80 °C for 6 h. Moreover, the complex catalyst can be recycled two times without any loss of catalytic activity.