The Synthesis Of5,6-Bicycle-diamide And The Study Of Their Extraction Properties

The rare earth elements are widely used in aerospace, catalysts, hydrogen storagematerials, high-end technology because of their special electronic structure and physicalchemical properties. But the coexistence paragenesis relations in deposit of the rare earthmetals and the interference from other metals, the separation and purification is critical.The pollution of heavy metal in the traditional view means copper, mercury, chromiumand so on; but it also including the environmental pollution caused by the loss of the rareearth elements in recent years. These pollution come into the picture of men’s life, short life ofthe equipment and high cost of handling method lead it is necessary to choose the rightapproach. Studies have shown that the solvent extraction could be an effective treatment ofheavy metal pollution.Solvent extraction is widely used for extracting rare earth elements due to its fastreaction rate, simplicity of operator and good separation effects. The products of chelatingability and radiolytic and hydrolytic degradation of amides are less detrimental to theextraction and separation processes than those of organic extractants. The amide ligands arewidely used in the extraction of rare earth and precious metals owning to their completelyincinerable, without affecting extraction, radiation resistance. The structure of the extractantswith O=C-N functional group is an important factor affecting the extraction performancewhich make their ligands for the Lewis acids. Bicycle-diamide is developed on the diamide,the unique rigid structure and appropriate atomic distances make them to be perfect ligard.The compounds could form chelate-type complex with the rare earth metal ions of their twofunctional groups, which is more conducive to their extraction. Also it is a cognition activatorof the nootropic class that has advanced to clinical trials. There is no specific company in thecountry to product the series of drug, so the research is necessary. Based on the above features,two different kinds of amide extractant were synthesized and extraction performance wasstudied. The main tasks are:(1)5,6-benzo-fused bicyclic amides compounds was tried to synthesized. Thecompounds have been characterized by high performance liquid, infrared spectrum, nuclearmagnetic resonance and Single crystal characterization. (2) N, N, N ’, N’-tetraoctyl-3-oxa-diglycolamide (TODGA) was synthesized. Thecompounds have been characterized characterized by high performance liquid, infraredspectrum, nuclear magnetic resonance.(3) The extraction mechanism and behavior of rare earth elements in hydrochloric acidextraction with TODGA extractants were investigated. The influence of extractantconcentration, hydrochloric acid concentration and temperature on the extraction wereinvestigated and the extracted species were analyzed by infrared spectrum.(4) Using dimethylbenzene, normal octane, dichloromethane, cyclohexane, normaldodecane as diluent, the effects of diluent on the distribution ratio were investigated. Theextraction distribution ratio of rare earth elements raises with the increase in the concentrationof hydrochloric acid. Also the proportion of the formation of complexes between theextractant and rare earth elements. There is a difference for the three metal ions of theextraction ability, so initial separation of the light and heavy rare earths could be achieved.(5) The effect of temperature on the extraction distribution ratios was discussed, itshowed that all of the extraction reaction is exothermic reaction. Decreasing temperature willbe favorable to the extraction reactions.