ИСТИНА

The project is aimed at solving the fundamental scientific problem - studying the processes of photoexcitation energy transfer and determining the patterns of temperature changes in the luminescent characteristics of new rare earth elements mixed compounds with ligands based on N-heterocyclic compounds. The relevance of the project is related to the study of temperature influence on the luminescent characteristics of a number of new complexes - candidates for luminescent temperature sensors. Fluorescent thermometry is indispensable in various areas where non-contact temperature measurement is required, for example, in moving and extremely small objects, or when physical contact is fundamentally impossible. Therefore, the development of nanoscale temperature sensors with a long luminescence lifetime, which is orders of magnitude longer than the emission time of fluorescent biomolecules, will be extremely important for use in chemistry, biology, and medicine. The development of efficient optical temperature sensors requires a deep understanding of the mechanisms leading to thermal luminescence quenching and knowledge of photoexcitation energy transfer schemes in complex mixed systems that include organic ligands, counterions, and several different rare earth ions. The main objectives of the project are to measure the spectral and luminescent properties of mixed complexes of rare earth elements (europium, terbium, samarium) with ligands based on N-heterocyclic compounds; observation and study of temperature changes in the luminescence of mixed complexes in various solvents; experimental measurement and calculation of such parameters as luminescence quantum yield, excited state lifetime, asymmetry factor; determining the dependence of luminescent parameters on the coordination environment of the rare-earth ion and revealing the role of photoexcitation energy transfer processes. As a result of the project, the mechanisms of temperature luminescence quenching in mixed complexes of rare earth elements compounds with ligands based on N-heterocyclic compounds will be established for the first time, and the ratios of rare earth ions in mixed complexes with the highest temperature coefficient of sensitivity will be selected for the first time. The novelty of the project will be the use of time-resolved luminescence spectroscopy to analyze the mechanisms of thermal quenching in mixed rare earth elements complexes and to establish the role and degree of different luminescent forms of rare earth ions complexes participation. To improve the accuracy of temperature measurements and increase the temperature sensitivity coefficient, a multiparametric approach will be applied for the first time: the simultaneous use of several luminescence characteristics - luminescence intensity (the ratio of the intensities of the luminescence bands of different ions), the asymmetry coefficient and the luminescence lifetime of a particular resonant transition. This method, developed by the authors of the application and having no analogues, has recently been successfully applied to determine the pH of an aqueous medium in a wide range of values, but in relation to mixed complexes and temperature measurements it will be applied for the first time. The results of the performed research will be a scientific basis for the development and optimization of the properties of compounds with ions of rare earth elements for their use as temperature sensors in nanomedicine, chemistry, and biology. The team of the country's leading university with different research experience will work on the implementation of the work: a young initiative leader, an experienced teacher with experience, a young research engineer and a master's student. When performing the work, new fundamental world-class results will be obtained and published in leading world and Russian publications, as well as reported at authoritative Russian and international conferences.

Работы по исследованию фотофизических свойств и устойчивости комплексов f-элементов проводятся исполнителями Проекта в течение последних 9 лет. Группа имеет большой опыт в проведении фотолюминесцентных исследований. Коллективом исполнителей ране было показано, что комплексы лантаноидов(III) с этими лигандами обладают высокой растворимостью, и в то же время имеют хорошие люминесцентные свойства и способны давать гладкие пленки. Расширяя набор органических тетрадентатных лигандов, содержащих одновременно жесткие и мягкие координационные центры, были получены гетероциклические дифосфиноксиды, содержащие структурный фрагмент пиридина, бипиридила и фенантролина. Также были исследованы их комплексы с ионами лантаноидов современными физико-химическими методами. Авторами заявки в 2015-2020 гг. проведены детальные спектрально-люминесцентные исследования органо- и водорастворимых комплексов европия с N-гетероциклическими лигандами в растворах (ацетонитрил, вода, тяжелая вода) и твердом виде (порошки, пленки). Помимо комплексов европия научная группа авторов заявки изучала люминесцентные свойства наноалмазов, гуминовых веществ и фотосинтетических пигментов заленых серных бактерий. У руководителя Проекта имеется опыт руководства научными проектами (грант РФФИ "Мой первый грант"). Руководитель проекта участвует в командных исследованиях (в том числе междисциплинарных) в других проектах, работает в коллективе над научными задачами, свидетельством чего являются совместные публикации с партнерами, в том числе младшими коллегами - студентами.