Tag Archive for Smirnov

RSC Adv., 2017, 7, 10070-10073

A.S. Smirnov, D.N. Nikolaev, V.V. Gurzhiy, S.N. Smirnov, V.S. Suslonov, A.V. Garabadzhiu, P.B. Davidovich

“Conformational stabilization of isatin Schiff bases – biologically active chemical probes”

RSC Adv., 2017, 7, 10070-10073
DOI: 10.1039/c6ra26779c

Isatin Schiff base derivatives have a wide range of biological effects. Unfortunately, these compounds possess a serious topological shortcoming: the conformational E ⇆ Z interconversion. Two ways of conformation stabilization are reported here: complexation with metals that stabilize the E-conformer and substitution in the 4th position of the isatin core stabilizing the Z-form.

DPX 300

Trableshoting of cooling sistem of Bruker DPX 300.

Rus. J. Coord. Chem., 2016, 42, 178-186

E.A. Katlenok, A.A. Zolotarev, A.Yu. Ivanov, S.N. Smirnov, R.I. Baichurin, K.P. Balashev

“Complexes of Ir(III) and Pt(II) with Cyclometallated 2-Phenylbenzothiazole and Chelating Diethyldithiocarbamate and O-Ethyldithiocarbonate Ions: Structures and Optical and Electrochemical Properties”

Rus. J. Coord. Chem., 2016, 42, 178-186

It is shown by X-ray diffraction analysis, IR spectroscopy, and 1Н, 13С{1H}, and 195Pt NMR spectroscopy that the Pt(II) and octahedral Ir(III) complexes with metallated 2-phenylbenzothiazole and chelating diethyldithiocarbamate and O-ethyldithiocarbonate ions have the square and cis-C,C structure, respectively. The highest occupied and lowest unoccupied molecular orbitals of the complexes determining their long-wavelength absorption, phosphorescence, and one-electron oxidation and reduction are assigned to those predominantly localized on the mixed p(S)/d(M) and π* orbitals of the metallated ligand. The cathodic shift of the oxidation voltammogram and the bathochromic phosphorescence shift of the Pt(II) complex with the О-ethyldithiocarbonate ion are attributed to the enhanced donor–acceptor interaction of the donor S atoms of the ligand with Pt(II). The structural data are deposited with the Cambridge Crystallographic Data Centre (CIF files CCDC nos. 1058768 (Ia) and 1058767 (IIb)).

Inorg. Chem. 2016

V.V. Sivchik, E.V. Grachova, A.S. Melnikov, S.N. Smirnov, A.Yu. Ivanov, P.Hirva, S.P. Tunik, I.O. Koshevoy
“Solid-State and Solution Metallophilic Aggregation of a Cationic [Pt(NCN)L]+ Cyclometalated Complex”

Inorg. Chem., 2016, ASAP

The noncovalent intermolecular interactions (π–π stacking, metallophilic bonding) of the cyclometalated complexes [Pt(NCN)L]+X (NCN = dipyridylbenzene, L = pyridine (1), acetonitrile (2)) are determined by the steric properties of the ancillary ligands L in the solid state and in solution, while the nature of the counterion X (X = PF6, ClO4, CF3SO3) affects the molecular arrangement of 2·X in the crystal medium. According to the variable-temperature X-ray diffraction measurements, the extensive Pt···Pt interactions and π-stacking in 2·X are significantly temperature-dependent. The variable concentration 1H and diffusion coefficients NMR measurements reveal that 2·X exists in the monomeric form in dilute solutions at 298 K, while upon increase in concentration [Pt(NCN)(NCMe)]+ cations undergo the formation of the ground-state oligomeric aggregates with an average aggregation number of ∼3. The photoluminescent characteristics of 1 and 2·X are largely determined by the intermolecular aggregation. For the discrete molecules the emission properties are assigned to metal perturbed IL charge transfer mixed with some MLCT contribution. In the case of oligomers 2·X the luminescence is significantly red-shifted with respect to 1 and originates mainly from the 3MMLCT excited states. The emission energies depend on the structural arrangement in the crystal and on the complex concentration in solution, variation of which allows for the modulation of the emission color from greenish to deep red. In the solid state the lability of the ligands L leads to vapor-induced reversible transformation 1 ↔ 2 that is accompanied by the molecular reorganization and, consequently, dramatic change of the photophysical properties. Time-dependent density functional theory calculations adequately support the models proposed for the rationalization of the experimental observations.

Russian Journal of Coordination Chemistry, 2015, 41(6), 357-364

E.A. Katlenok, A.A. Zolotarev, A. U. Ivanov, S.N. Smirnov, R.I. Baychurin, K.P. Balashev

Title in rus: “Cтроение, оптические и электрохимические свойства биядерных платинированных комплексов 2-фенилбензотиазола с мостиковыми 2-меркаптопроизводными тиазолина, 1-метилимидазола и пиримидина”

Journal of Molecular Structure, 2014

P.B. Davidovich, D.S. Novikova, V.G. Tribulovich, S.N. Smirnov, V.V. Gurzhiy, G. Melino, A.V. Garabadzhiu

”First X-ray Structural Characterization of Isatin Schiff-Base Derivative. NMR and Theoretical Conformational Studies”

Journal of Molecular Structure, 20141075, 450-455

DOI: 10.1016/j.molstruc.2014.07.008

Isatin (1H-indole-2,3-dione) is an endogenous natural compound under intense development in medicinal chemistry. Here, we characterize isatin Schiff base derivative by X-ray crystallography. We describe a derivative that crystallizes E-isomer form in the triclinic space group P1; a=5.9580 (4) Å, b=8.4184 (7) Å, c=14.1801 (14) Å, α = 73.962 (8)°, β =83.184 (7)°, γ = 81.143 (6)°. NMR data show that E-conformer interconverts to the Z-conformer when dissolved, this equilibrium weakly depends on the solvent type. The Z-isomer geometry and the energetics of ΔEE-Z interconversion barriers were determined by quantum chemical calculations. The isomers are further characterized by means of FT-IR and UV-Vis spectroscopy.

Internal seminar 14.11.2013

Sergey Smirnov presented a talk about cryoprobes and their advantages and disadvantages.

Sergey Smirnov and Andrey Gurinov got certificates

Employees of the Center for Magnetic Resonance Sergey Smirnov and Andrey Gurinov have completed the training courses in the University of Regensburg in Germany and got certificates.

Filled the magnets with liquid Helium

2013-05-29 11.37.432013-05-29 12.13.31

Our contribution to the 9th Winter Youth School Conference Spinus 2012

9th Winter Youth School Conference Spinus 2012, St. Petersburg, Russia, 3-8.12.2012.

a) Lecture
P.M. Tolstoy, H.-H. Limbach, N.S. Golubev, G.S. Denisov, I.G. Shenderovich, S.N. Smirnov, B. Koeppe, J. Guo, S.A. Pylaeva, E.Yu. Tupikina
“Correlations between NMR parameters and hydrogen bond geometry”;

b) Oral presentation
S.A. Pylaeva, B. Koeppe, P.M. Tolstoy, G.S. Denisov
“Solvent effects on the geometry of the OHN hydrogen bond in the 2-methylpyridine – chloroacetic acid complex”

c) Poster
E.Yu. Tupikina, P.M. Tolstoy, S.A. Pylaeva, S.N. Smirnov, G.S. Denisov
“CH acid 1,1-dinitroethan as a hydrogen bond proton donor”