The Laborartory Head – PAVLISHCHUK, Vitaly V.

Corresponding Member of NAS of Ukraine, Doctor of chemical sciences, Professor

L.V.Pisarzhevskii Institute of physical chemistry of NAS of Ukraine

Prosp. Nauki 31, Kiev 03039, Ukraine

tel.: 38 (044) 525-42-24; 38 (044) 525-62-24; fax 38 (044) 525-62-16;

e-mail: shchuk@inphyschem.nas-kiev.ua

Laboratory of spectroscopy of polymers at the Department of free radicals was created in the Institute in 1994. It was headed by Candidate of physico-mathematical sciences V.G.Golovatyy. The laboratory worked on development of fundamental principles of mass-spectrometry with field ionization, in particular, theoretical bases for the method of ionization by electric field were established, the principles of molecular ions and fragments desorption from the surface in conditions of mass-spectrometry experiment were systematically studied. V.G.Golovatyy with co-workers developed a number of new methods for manufacturing of field ion sources with metallic coating from different metal atoms, in particular, iron, nicker, copper, zinc, gold. These works allowed to extend significantly the possibilities of mass-spectrometry method for studies of compounds, which require soft ionization conditions. The methods, developed in the Laboratory, were widely used in the studies in the field of chemical structure and kinetics, catalysis, physico-inorganic chemistry, at solving of several medico-biological problems, studies of adsorption of several substrates.

Since 2004 the Laboratory is headed by Doctor of chemical sciences V.V.Pavlishchuk. In this period fundamental studies were started in the Laboratory, which were focused on elucidation of relation between molecular and crystal structure of polynuclear complexes of transition metals and their physical properties, such as magnetic, adsorption, catalytic properties, etc. In particular, main electronic and topological factors, which make influence on the type and energy of exchange interactions in molecular systems with spin exchange were revealed, it was found that indirect exchange interactions, peculiar to such complexes, resulted in occurrence of magnetic ordering within one molecule. It was found that the type of magnetic ordering depended both on the type of exchange interactions and on topology of metal ions location in polynuclear core. Significant attention is devoted to development of non-traditional methods for preparation of transition metals nanooxides and different composite materials on their basis via activation by mechanochemical method, by microwave irradiation and solvothermal decomposition of polynuclear complexes. It was shown that obtained nanomagnetic composites were promising candidates for use as adsorbents for selective express-extraction of certain classes of proteins from blood serum, in particular, globulines.

Main directions of studies

Studies in several actual directions of modern physico-inorganic chemistry are carried out in the Laboratory, in particular:

theory of chemical structure of coordination compounds;

molecular magnetism of polynuclear complexes of 3d and 4f metals;

processes with electron transfer: electrochemistry of coordination compounds, kinetics and mechanisms of redox-reactions;

physical chemistry of nanosized magnetic particles;

adsorption processes involving coordination polymers.

Scientific studies are carried out with the use of physical methods of research:

– mass-spectrometry (molecules ionization by electron impact, strong electric field, fast atoms bombardment) for identification of compounds and their structure examination;

– radiospectroscopy (NMR, ESR) for obtaining of qualitative and quantitative characteristics of different chemical, electrochemical, photochemical and other processes;

– transmitting electron microscopy of nanosized and nanostructured compounds, composites and materials.

The most important recent results

The relation between molecular and crystal structure of coordination polymers and polynuclear complexes of transition metals and such physical properties, as magnetic, adsorption, catalytic, etc., was found. In particular, main electronic and topological factors which make influence on the type and energy of exchange interactions in molecular systems with spin exchange were revealed. It was found that indirect antiferromagnetic exchange interactions, peculiar to such complexes, led to occurrence of local ferromagnetic ordering within one molecule; 1D coordination polymers with ferro- and ferrimagnetic ordering in the chain were obtained.

T/K                                                               T/K

The Curie-Weiss plot for 1D Molecular magnet [Co(Benzoate)2]n (C- 5.95 cm3Kmol-1)

The plot of magnetization vs T for [Co(Benzoate)2]n in zero-field (ZFC) and magnetic field (FC, H=5 Oe)

New approach to creation of ferrimagnetic nanooxides and nanocomposites based thereon by thermolysis or microwave activation of polynuclear complexes was grounded and developed, which allowed to obtain a number of superparamagnetics with high Curie temperature and narrow distribution of nanoparticles on size;

The method for magnetic express-separation of immunoglobulies from blood serum was developed, which allowed to achieve significant increase of the efficiency of their extraction; new magnetic luminescent nanocomposite CoFe₂O₄@SiO₂@Gd₂O₃:Eu₂O₃ was created and it was found that its particles were able to penetrate to macrophage cells, which can find application both for diagnostics and treatment of oncologic diseases by hyperthermia.

It was shown that changes of structural parameters of porous coordination polymers (PCP) with variation of temperature or quantity of adsorbed substrate have symbate character, which allows to obtain important information about change of molecular structure of PCP at pores filling by adsorbate.

PhD students of the Laboratory at work on their PhD projects

Scientific collaboration

Chemical Department of Drexel University, Philadelphia, USA – Prof. A.W.Addison – Agreement on cooperation in the field of physico-inorganic chemistry of polynuclear complexes.

Equipe Organométalliques et Matériaux Moléculaires, Sciences Chimiques de Rennes, UMR UR1-CNRS – Prof. L. Ouahab – grants in the frames of Agreement on cooperation between NAS of Ukraine and CNRS – studies of magnetic properties of metal-radical complexes and nanoparticles

Chemical Department of Memorial University, Canada, Prof. L. Thompson – studies of molecular magnetism of polynuclear complexes;

N. S. Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences – academicians V.M.Novotortsev and I.L.Eremenko – within INTAS grant 2004-2007 – studies of molecular and crystal structure of polynuclear complexes.

Selected publications

• V.V. Pavlishchuk, S.V. Kolotilov, A.W. Addison, M.J. Prushan,  D. Schollmeyer, L.K.Thompson, E.A.Goreshnik A Tetrameric Nickel (II) “Chair” with both Antiferromagnetic Internal Coupling and Ferromagnetic Spin Alignment Angew. Chem. Int. Ed. 2001, 40, No. 24, 4734-4737.
• S.V. Kolotilov, O. Shvets, O. Cador, N. Kasian, V. G. Pavlov, L. Ouahab, V. G. Ilyin, V. V. Pavlishchuk Synthesis, structure and magnetic properties of porous magnetic composite, based on MCM-41 molecular sieve with Fe3O4 nanoparticles J. Solid State Chem. 2006, 179, 8, 2426-2432.
• Gavrilenko K.S., Punin S.V., Cador O., Golhen S., Ouahab L., Pavlishchuk V.V. Synthesis, Structure, and Magnetism of Heterometallic Carboxylate Complexes [Mn^III₂M^II₄O₂(PhCOO)₁₀(DMF)₄], M = Mn^II, Co^II, Ni^II, Inorg. Chem., 2005, 44(16), 5903-5910.
• Gavrilenko K.S., Punin S.V., Cador O., Golhen S., Ouahab L., Pavlishchuk V.V. In situ generation of carboxylate: an efficient strategy for a one-pot synthesis of homo- and heterometallic polynuclear complexes, J. Am. Chem. Soc., 2005, 127(35), 12246-12253.
• V. N. Dorofeeva, S. V. Kolotilov, M. A. Kiskin, R. A. Polunin, Z. V. Dobrokhotova, O. Cador, S. Golhen, L. Ouahab, I. L. Eremenko, V. M. Novotortsev 2D Porous Honeycomb Polymers versus Discrete Nanocubes from Trigonal Trinuclear Complexes and Ligands with Variable Topology Chem. Eur. J., 2012, 18, 5006 – 5012.
• V. Pavlishchuk, S. V. Kolotilov, M. Zeller, O. V. Shvets, I. O. Fritsky, S. E. Lofland, A. W. Addison, A. D. Hunter Magnetic and Sorption Properties of Supramolecular Systems Based on Pentanuclear Copper(II) 12-Metallacrown-4 Complexes and Isomeric Phthalates: Structural Modeling of the Different Stages of Alcohol Absorption Eur. J. Inorg. Chem., 2011, 4826–4836.
• R. A. Polunin, S. V. Kolotilov, M. A. Kiskin, O. Cador, S. Golhen, O. V. Shvets, L. Ouahab, Z. V. Dobrokhotova, V. I. Ovcharenko, I. L. Eremenko, V. M. Novotortsev, V. V. Pavlishchuk Structural flexibility and sorption properties of 2D porous coordination polymers constructed from trinuclear heterometallic pivalates and 4,4′-bipyridine Eur. J. Inorg. Chem., 2011, 4985–4992.
• E. A. Mikhalyova, S. V. Kolotilov, O. Cador, M. Zeller, S. Trofimenko, L. Ouahab, A. W. Addison, V. V. Pavlishchuk, A. D. Hunter The role of the bridging group in exchange coupling in dinuclear homo- and heterometallic Ni(II) and Co(II) complexes with oxalate, oxamidate and dithiooxamidate bridges Dalton Trans., 2012, 41 (37), 11319 – 11329.
• E. A. Mikhalyova, S. V. Kolotilov, M. Zeller, L. K. Thompson, A. W. Addison, V. V. Pavlishchuk, A. D. Hunter Synthesis, structure and magnetic properties of Nd3+ and Pr3+ 2D polymers with tetrafluoro-p-phthalate Dalton Trans. 2011, 40, 10989–10996.
• R. A. Polunin, S. V. Kolotilov, M. A. Kiskin, O. Cador, E. A. Mikhalyova, A. S. Lytvynenko, S. Golhen, L. Ouahab, V. I. Ovcharenko, I. L. Eremenko, V. M. Novotortsev, V. V. Pavlishchuk Topology Control of Porous Coordination Polymers by Building Block Symmetry, Eur. J. Inorg. Chem., 2010, 5055–5057