The history of the Laboratory of Structural Chemistry (originally — the Laboratory of Radiospectroscopy) dates back to the cold Christmas of 1970 when the 28 years old Vadim Pestunovich, the Founder of the Laboratory, visited Irkutsk on the invitation of the former director of the Institute, the Corresponding Member of the Latvian Academy of Sciences professor Mikhail G. Voronkov. Those days it was something unbelievable and even ridiculous that somebody could move from one of the “prosperous” European city like Riga to the depth of the cold-beaten Siberia. Some day afterwards Vadim Pestunovich confessed that an original purpose of his visit was just to have a look at the Institute and to get acquainted with its personnel but just on arrival he got a crush on Siberia, Siberian people and Irkutsk Institute of Organic Chemistry (the former name of the Institute), so that he immediately agreed to head this newly organized laboratory. Within two months after this event the Laboratory of Radiospectroscopy was officially organized with a staff of 3 people (Vadim Pestunovich, Inna Kalikhman and Vladimir Voronov) and one PhD student (Tamara Vakul’skaya) and equipped with the available old-fashioned (if looking from nowadays) NMR and EPR spectrometers.
That it how it was in the very beginning. Later, in 1978, the Laboratory of Radiospectroscopy was renamed to the Laboratory of Structural Chemistry. In the meantime, during the first year two more people joined scientific staff of the Laboratory, namely Mikhail Larin and Valery Sidorkin who graduated from the Department of Physics of the State University of Irkutsk. A bit later three more newcomers arrived from Riga and joined Laboratory staff — namely, Valentin Feshin, Elena Tsetlina and Stanislav Tandura. By September 1971 the staff of the Laboratory totaled to 10 members, while one year later there was already 16 people. Within the Laboratory, Vadim Pestunovich established four research groups — the Group of NMR Spectroscopy (Inna Kalikhman), the Group of NQR Spectroscopy (Valentin Feshin), the Group of EPR and Polarography (Tamara Vakul’skaya) and the Group of Theoretical Chemistry (Valery Sidorkin). The Laboratory was equipped with three Czech NMR spectrometers (operating at 60, 80 and 100 MHz) by “Tesla” and later, in 1980, the Japanese Fourier-transform pulse NMR spectrometer (90 MHz) by “Jeol” was purchased.
Hard times of 1990-s were marked with a series of the Laboratory publications dealing with the NMR, EPR and NQR investigations of the stereoelectronic structure and reaction mechanisms of the heteroatomic and elementoorganic compounds synthesized in the Institute which resulted in the discovery of new reactions and rearrangements of the silicon, germanium and tin derivatives of organic compounds, as well as in the development of the multinuclear NMR techniques now known worldwide. One of the most significant achievements of these studies was that dealing with the experimental and theoretical elucidation of the nature of the trans-annular bond in silatranes and in other compounds of hypervalent silicon done under the supervision of Professor Pestunovich, the Founder and the Head of the Laboratory. In the interim from early 80-s through late 90-s Laboratory of Structural Chemistry organized three international conferences on “NMR Spectroscopy of Heavy Nuclei” sponsored by the Siberian Branch of the Russian Academy of Sciences which resulted in the formation of the Laboratory international image.
This period is marked with a series of important scientific results reached at in the Laboratory as follows: the elucidation of chemical structure, tautomeric rearrangements and reaction mechanisms of the nitrogen-containing heterocycles by means of 15N NMR (Mikhail Larin, Ludmila Larina); EPR monitoring of chemical reactions including one-electron transfer in the formation of radical cation — radical anion pairs (Tamara Vakul’skaya); NQR structural studies of chloroorganic compounds (Gennady Dolgushin). Those days a number of the Laboratory staff members got their DSc Degrees (the highest scientific degree in Russia) — Vladimir Voronov, Valentin Feshin, Mark Sigalov, Inna Kalikhman, Stanislav Tandura, Valery Turchaninov, Valery Sidorkin, Ludmila Larina, Tamara Vakul’skaya. They produced a number of high-rank publications (including books and chapters in the international periodic editions) and presented a series of talks and plenary lectures on the scientific meetings worldwide. The most prominent event in the life of the Laboratory of 1990-s is the purchase and installation of the Bruker superconducting NMR spectrometer DPX-400 in 1999. Indeed, it was a turning point driving Laboratory from the Past to a New Epoch.
The beginning of the XXI century saddened the life of the Laboratory by a tragic event — the death of its establisher and supervisor, an outstanding and world-renowned scientist, the Laureate of a State Award in Chemistry, Professor Vadim Aleksandrovich Pestunovich on July 4, 2004. It was a hard and an irreparable loss for Laboratory, for Institute and for World Science. The Laboratory continued research in the field of Structural Chemistry but, alas, without its Founder and Scientific Supervisor.
In this critical period a new head of the Laboratory, professor Leonid Krivdin has started his activity trying to preserve existing scientific directions and launching a new development program based on the high-level NMR-oriented quantum chemical calculations and their applications in structural studies of heteroatomic and elementoorganic compounds. The latter were conducted in collaboration and with the help of the internationally known theoretical groups of Professor Ruben Contreras (University of Buenos Aires), Professor Stephan Sauer (University of Copenhagen) and Professor Michael Barfield (University of Arizona). The new high-accuracy high-level quantum-chemical methods of the calculation of magnetic shielding constants (chemical shifts) and spin-spin coupling constants have been carried out within the Density Functional Theory and Second Order Polarization Propagator Approach, SOPPA, together with that in combination with Coupled Clusters Theory, SOPPA(CC2) and SOPPA(CCSD), which are now internationally recognized and widely cited in world literature.
In the first decade of a new century a number of young and enthusiastic PhD students supervised by Leonid Krivdin were conducting their research in the field of NMR-oriented high-level quantum-chemical calculations and successfully defended their PhD theses (Yury Rusakov, Natalia Scherbina, Spartak Khutsishvili, Kirill Chernyshev, Sergey Fedorov). Almost all of them joined research Laboratory staff and actually, this was the second birth of the Laboratory which was also accomplished by the installation of a new Bruker superconducting NMR spectrometer AVANCE-400 in 2004 and a new Bruker pulse EPR spectrometer ELEXSYS E-580 in 2009. In 2007 the Head of the Laboratory, Professor Krivdin becomes the Editor of Magnetic Resonance in Chemistry, the internationally recognized leading journal in the field of NMR Spectroscopy and its applications in Chemistry.
Recent years are marked with a strengthening of a theoretical background of the Laboratory which is becoming an internationally recognized leading team and a driving engine in the field of the high-level NMR-oriented quantum chemical calculations (Leonid Krivdin, Yury Rusakov, Irina Rusakova, Sergey Fedorov, Kirill Chernyshev, Elena Chirkina, Dmitry Samultsev, Valentin Semenov). Of an utmost importance are the results on the full four-component relativistic calculations of spin-spin coupling constants involving NMR “heavy” nuclei which made up an internationally recognized breakthrough in the NMR-oriented relativistic calculations (Yury Rusakov and Irina Rusakova). Traditionally, further development of the multinuclear multipulse NMR techniques provided new perspectives in structural elucidation of organic and elementoorganic compounds synthesized in the Institute (Ludmila Larina, Alexander Albanov, Igor Ushakov et al.), including those based on 13C NMR (Igor Ushakov), 15N NMR (Ludmila Larina), 29Si NMR (Alexander Albanov) and 31P NMR (Sergey Fedorov). In the EPR group of the Laboratory a good deal of interest is traditionally focused on the one-electron transfer radical processes. However, in the recent years this interest is changing in favor of the magnetic properties, formation and evolution of the metal-containing nanoparticles with natural and synthetic polymer coating.
Basically, the research activities of the highly qualified personnel of the Laboratory of Structural Chemistry equipped with the modern NMR and EPR technique as well as powerful computational facilities originate in the scientific programs conducted in A.E. Favorsky Irkutsk Institute of Chemistry of the Siberian Branch of the Russian Academy of Sciences in the field of the high technological multifunctional materials and medical drug precursors based on acetylene (Scientific School of Academician Trofimov) and silicon (Scientific School of Academician Voronkov).
Research staff of the Laboratory of Structural Chemistry includes 10 members and 1 PhD student. Among those, 3 members have DSc and 7 members have PhD scientific degrees, as follows:
Head of the Laboratory:
Krivdin, Leonid (Prof., DSc) http://krivdin.irk.ru
Professor Leonid Krivdin
Head of the Laboratory
NMR elucidation of chemical structure — a breakthrough
to the Unknown
Areas of Research
Historically, three scientific directions of the laboratory research were formed which are developing at present:
1. Structural studies of organic and elementoorganic compounds by means of multinuclear multipulse NMR spectroscopy.
2. Theory and stereochemical applications of the high-level NMR-oriented quantum-chemical calculations.
3. EPR studies of intermediate and stable paramagnetic systems including metal-containing nanoparticles with natural and synthetic polymer coating.
Investigation of silver and gold nanoparticles coated with natural polysaccharides by means of EPR spectroscopy
Systematic stereoelectronic studies of the high technological multifunctional materials and medical drug precursors based on acetylene and silicon synthesized in A.E. Favorsky Irkutsk Institute of Chemistry of the Siberian Branch of the Russian Academy of Sciences are carried out by means of NMR and EPR spectroscopy together with high-level NMR-oriented quantum-chemical calculations. In this line, stereochemical structures of a wide variety of phosphorous- silicon- and selenoorganic compounds have been established based on the experimental measurements in combination with the high-level theoretical calculations of chemical shifts and spin-spin coupling constants involving 31P, 29Si and 77Se nuclei. A special attention has been focused on the stereochemical applications of the marked stereospecificity of these parameters in respect with the lone pair effects, intramolecular orbital interactions as well as some other stereoelectronic effects. In particular, conformational analysis together with the diastereotopic assignments in the series of selenosugars and a number of organoselenium heterocycles — the derivatives of thiaselenetane, selenoasilol, thiaselenol, thiaselenolane and dihydrothiaselenine — have been carried out by means of 77Se-1Н spin-spin coupling constants. A systematic analysis of factors influencing the accuracy of the calculation of chemical shifts and spin-spin coupling constants has been performed using a number of the DFT and SOPPA methods taking into account the level of theory, the quality of the basis sets, the relativistic effects, rovibrational corrections, solvent effects and conformational effects. Computational schemes of the full four-component relativistic calculations of spin-spin coupling constants involving NMR “heavy” nuclei have been carried out. Also, the nanoparticles of silver and gold coated with natural polysaccharides like arabinogalactane, carraginane, and galactomannane proved to be efficient medications were investigated by means of pulse EPR techniques.
· Krivdin, Leonid — Honorary Medal “300 Years of Mikhail Lomonosov” (2012)
· Vakul’skaya, Tamara; Larina, Ludmila; Albanov, Alexander — Honorary Medals “350 Years of Irkutsk” (2012)
· Krivdin, Leonid — Diploma of the Governor of Irkutsk Region (2011)
· Chernyshev, Kirill — Diploma “Best PhD Students of the Russian Academy of Sciences” (2008)
· Vakul’skaya, Tamara; Larina, Ludmila; Albanov, Alexander — Honorary Medals of the Siberian Branch of the Russian Academy of Sciences “Silver Sigma” (2007)
· Krivdin, Leonid — Diploma of the Ministry of Higher Education and Science of the Russian Federation (2005)
Scientific Degrees and Promotions
Since the establishment of the Laboratory of Structural Chemistry its staff members and PhD students defended 10 DSc and 25 PhD theses, the last one by Sergey Fedorov (PhD) on “Stereochemical studies of unsaturated phosphines and phosphine chalcogenides using phosphorous-proton spin-spin coupling constants” (Supervisor — Prof. Leonid Krivdin).
Recent Grants and Contracts
Grant No 11-03-00022a by Russian Fund for Basic Research “Structural and stereochemical studies of the unsaturated phosphorous and selenium containing compounds by means of NMR and quantum chemistry” (Supervisor — Prof. Leonid Krivdin).
· Krivdin L.B., Rusakov Yu.Yu. Structural and Stereochemical Applications of Computational NMR Using 29Si-1H and 77Se-1H Indirect Spin-Spin Coupling Constants. In: Encyclopedia of Magnetic Resonance. Wiley. — London, 2014.
· Rusakov Yu.Yu., Krivdin L.B. Modern quantum chemical methods for calculating spin ± spin coupling constants: theoretical basis and structural applications in chemistry // Russ. Chem. Rev. — 2013. — Т. 82. — N 2. — С 99-130.
· Rusakova I.L., Krivdin L.B. Karplus dependence of spin-spin coupling constants revisited theoretically. Part 1: Second-order double perturbation theory // Phys. Chem. Chem. Phys. — 2013. — V. 15. — P. 18195-18203.
· Rusakova I.L., Krivdin L.B., Rusakov Yu.Yu., Trofimov A.B. Algebraic—diagrammatic construction polarization propagator approach to indirect nuclear spin—spin coupling constants // J. Chem. Phys. — 2012. — V. 137, N 4. — P. 044119.
· Chernyshev K.A., Larina L.I., Chirkina E.A., Krivdin L.B. The effects of intramolecular and intermolecular coordination on 31P nuclear shielding: phosphorylated azoles // Magn. Reson. Chem. — 2012. — v. 50, N 2. — P. 120–127.
· Vakulskaya T. I., Larina., L.I. Radical anions of flavonoids // Magn. Reson Chem. — 2011. V. 49, N 8. — P. 508-513.
· Larina L.I., Lopyrev V.A. Nitroazoles: Synthesis, Structure and Application. Springer. — New York, 2009. — 446 p.