ИСТИНА

Currently, the most effective and promising method of obtaining energy is nuclear decay reactions. The main obstacle to the widespread use of nuclear energy is the formation of large amounts of radioactive waste. If the methods of separating uranium, neptunium and plutonium from these wastes are well-developed (PUREX, UNEX are processes used in modern technological schemes), then the isolation and separation of minor actinides (americium, curium, California, etc.) is one of the urgent tasks of modern research and industrial chemistry. The most promising way to solve this problem is the group liquid extraction of 5-f elements followed by their chemical separation. The proposed project is aimed at finding new effective extractants that combine "soft" and "hard" metal coordination centers in their structure. Serious attention is also expected to be paid to the simplicity of obtaining the appropriate compounds through the use of non-catalytic transformations, without the use of transition metal catalysts, as well as the possibility of scaling the synthesis of target ligands from hundreds of milligrams to tens of grams or more. Our group has been actively searching for group extractants for the selective separation of actinides and lanthanides for 15 years. Heterocyclic ligands containing metal ion binding centers of different types in their structure seem to be the most promising to us. Thus, diamides of 2,2’-bipyridyl-6,6’-dicarboxylic acid have been widely studied. Recently, the bis-phosphine oxides of the pyridine and 2,2’-bipyridyl series have been studied. In this work, it is planned both to obtain new ligands based on pyridine, 2,2'-bipyridyl and related structures containing oxygen atoms of amide, phosphonate and phosphoramide groups as "rigid" metal binding centers, and to study their interaction with 4f and 5-f elements in order to find the most suitable compounds for laboratory testing and industrial use for separating mixtures of lanthanides and actinides. Obtaining the appropriate complexes, possible study of thermodynamic binding constants and test extraction experiments will allow us to identify structure-property ratios for extractants of this type, determine the optimal conditions for extraction separation and deepen our understanding of the processes occurring during separation.

1. Впервые будет проведен синтез серии экстрагентов различной гетероциклической природы, содержащие мягкие (азотные) центры связывания в составе гетероциклического каркаса, в комплексе с различными жесткими (кислородными) центрами связывания в составе функциональных групп (амидных, фосфонатных, фосфорамидных и тп). Строение, конформационная динамика и свойства полученных веществ будут систематически сопоставлены со строением уже известных жестких-мягких гибридных экстрагентов. 2. Впервые будет получена серия комплексов 4-f- и 5-f-элементов (урана, тория и др) с неизвестными ранее лигандами и будет изучено их в различных фазах (газ, растворы, твердое тело). 3. Впервые будут определены факторы разделения 4-f и 5-f-элементов новыми гетероциклическими лигандами.