Siberian Branch of Russian Academy of Sciences

Current research

Research conducted in the group headed by Dr.Sc. A.V. Yurkovskaya, are aimed at elucidation of mechanism of reactions and structure, reactivity and dynamic behavior of short-lived intermediate radical particles in biologically important molecular systems and photoprocesses. In research we use high-power pulsed lasers for optical initiation of chemical reactions in NMR spectrometers and apply modern pulsed nuclear magnetic resonance methods to detect reaction products with polarized nuclear spins with microsecond time resolution. The creation of nonequilibrium spin systems is based on the important role of magnetic interactions in chemistry, namely, on the influence of electron and nuclear spins on the rate and yield of chemical and biological reactions. The method of chemically induced dynamic nuclear polarization (CIDNP) - has a high spectral sensitivity and selectivity, is used to study the reaction of radical intermediates of biomolecules in conditions close to physiological, as well as to study the dynamic processes involving protein molecules and nucleic acids. Research conducted by Dr. O.B.Morozova, Dr. N.N. Fishman, Dr. A.S. Kiryutin, postgraduates I.V. Zhukov and M.S. Panov on NMR spectrometers with operating frequencies for protons of 200, 300, 400 and 700 MHz.

For studies of nuclear spin hyperpolarization, induced by para-hydrogen and ortho-deuterium, a fully automated high-pressure set-up was designed and built0up by Dr. A.S. Kiryutin in 2016. The PHIP, ODIP and SABRE methods (Parahydrogen Induced Polarization; Ortodeuterium Induced Polarization; Signal Amplification By Reversible Exchange) are used to create nuclear spin hyperpolarization in the reaction of hydrogenation or polarization transfer with the interaction of the substrate molecule with the spin isomers of molecular hydrogen. Research in this area, carried out in cooperation with the group of theoretical chemistry under the leadership of Professor K. L. Ivanov are aimed at clarifying the mechanism and developing effective pulse sequences, as well as optimizing the magnetic field strength to hyperpolarize substrates and to maintain this polarization in long-lived spin states in order to increase the sensitivity of NMR spectroscopy and tomography. In 2017, Dr. A.S. Kiryutin and Dr.Sc. Yu. A. Grishin (ICKC SB RAS) bult-up an unique experimental setup based on a 400 MHz NMR spectrometer for fast switching of the magnetic field by positioning the sample in a stray magnetic field along the axis of a cryomagnet with a field of 9.4 T and for measurements in ultra-weak fields, which are several orders of magnitude lower than the Earth's field. In the NMR spectra, a high resolution is maintained at the level of 1 Hz, which is important for studying CIDNP, PHIP, DNP, as well as in studying dispersion of relaxation (I.V. Zhukov and M.S. Panov) for any magnetic nuclei over magnetic field range from 10 nT to 9.4 T with high spectral resolution at the level of individual atoms in the molecule.