RAS Nikolaev Institute of Inorganic Chemistry

Novosibirsk, Russia

RAS Nikolaev Institute of Inorganic Chemistry

Novosibirsk, Russia
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In solution, [Ln(H2O)n(dtpa)]2− chelates undergo a dynamic exchange between two enantiomers. The free energy of activation of intramolecular dynamics (for complexes of Pr to Ho) slightly increases with decreasing radius of the lanthanide cation. According to analysis of the paramagnetic lanthanide induced shifts (LIS) in NMR spectra, the structure of [Ho(H2O)n(dtpa)]2− in solution is similar to the related model found in the crystal state. It was found that complexes [Ln(H2O)n(dtpa)]2− may be used (due to the substantial temperature dependence of LIS) as NMR thermometric sensors for controlling the local temperature in aqueous medium. The investigated coordination compounds are suggested to apply as thermo-sensing contrast reagent for MRI diagnostics of cancer and inflammation. © 2017 Elsevier B.V.

Kozlova S.G.,RAS Nikolaev Institute of Inorganic Chemistry
JETP Letters | Year: 2016

The temperature dependence of the heat capacity at second-order phase transitions that were previously detected in the [Zn2(C8H4O4)2 · C6H12N2] metal-organic framework compound has been analyzed. The critical exponents have been obtained. It has been shown that the behavior of the heat capacity below the critical temperature of 60 K, which is attributed to the violation of the mirror symmetry of C2H12N6 molecules, is exponential. © 2016, Pleiades Publishing, Inc.

Lavrenova L.G.,RAS Nikolaev Institute of Inorganic Chemistry | Shakirova O.G.,Komsomolsk-on-Amur State Technical University
European Journal of Inorganic Chemistry | Year: 2013

We review herein the synthesis and investigation of iron(II) coordination compounds with 1,2,4-triazoles or tris(pyrazol-1-yl)methanes as ligands. Both groups of complexes demonstrate thermally induced spin crossover accompanied by thermochromism [pink (magenta) ↔white color change]. Factors that influence the nature and temperature of the spin crossover are discussed. © 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Danylyuk O.,Polish Academy of Sciences | Fedin V.P.,RAS Nikolaev Institute of Inorganic Chemistry
Crystal Growth and Design | Year: 2012

The crystal structure of the supramolecular exclusion complexes of cucurbit[6]uril with amino acid D-tryptophan and its decarboxylation product tryptamine have been determined. The supramolecular self-Assembly of the cucurbit[6]uril with aromatic guests is guided by the combination of ion-dipole, hydrogen bonding, and stacking interactions between indole rings and glycouril groups of cucurbit[6]uril and leads to the formation of helical nanotubules in the case of tryptophan and stacked columns in the case of tryptamine. The formation of the solid-state complexes is dependent on the type of salt used for solubilization of cucurbit[6]uril which is explained in terms of the specific coordination mode of cucurbit[6]uril with magnesium ion. © 2011 American Chemical Society.

Nizovtsev A.S.,RAS Nikolaev Institute of Inorganic Chemistry
Journal of Computational Chemistry | Year: 2013

We report detailed study focused on the electron density redistribution during the simple oxidative addition reaction being the crucial stage of various catalytic processes. The bonding evolution theory based on the electron localization function and Thom's catastrophe theory shows that activation of methane's CH bond by Pd atom consist of six elementary steps. The important feature revealed is the pronounced reorganization of Pd's outer core maxima corresponding to N-shell electrons of metal. Electronic rearrangements identified in this model reaction are likely to be the case in the more complex reactions of the same type involving transition metal compounds and, in principle, can be observed by modern ultrafast spectroscopy and diffraction techniques. © 2013 Wiley Periodicals, Inc.

Smolyakov B.S.,RAS Nikolaev Institute of Inorganic Chemistry
Applied Geochemistry | Year: 2012

The removal efficiency of water hyacinth for Zn, Cu, Pb and Cd after their entry into an undisturbed fresh water body was studied using minicosms placed within a reservoir. Variable parameters were water pH (6 or 8), single or multi-metal additions, and the plant biomass. The initial concentrations of Zn, Cu, Pb and Cd in water (500, 250, 250 and 50 μg/L, respectively) quickly decreased in the order Pb ≈ Cu ≫ Cd ≈ Zn in the first days. Metal removal was more efficient at pH 8 than at pH 6, and it was only slightly higher for single metals compared to multi-metal additions. After 8. days the remaining amounts of metals relative to their initial concentrations for multi-metal pollution treatments were 8% and 24% (Cu), 11% and 26% (Pb), 24% and 50% (Cd), and 18% and 57% (Zn) at pH 8 and pH 6, respectively. Increasing plant biomass promoted faster metal removal. The bioconcentration factor (the ratio of the metal concentration in whole plants to the initial metal concentration in water) exceeds 2000 for all metals (with the exception of Zn and Cd at pH 6). It was concluded that the water hyacinth can be successfully used for fast removal of metals in the initial stage of water body remediation. © 2012 Elsevier Ltd.

Larionov S.V.,RAS Nikolaev Institute of Inorganic Chemistry
Russian Journal of Coordination Chemistry/Koordinatsionnaya Khimiya | Year: 2012

Some problems of the chemistry of coordination metal compounds with chiral ligands based on natural organic compounds, especially terpenes, are generalized. The results on the synthesis and study of the structure and properties of the chiral transition metal complexes with several groups of new "hybrid" ligands based on monoterpenes pinene, (+)-3-carene, and limonene and sesquiterpene caryophyllene are considered. © 2012 Pleiades Publishing, Ltd.

Peresypkina E.V.,RAS Nikolaev Institute of Inorganic Chemistry | Vostrikova K.E.,RAS Nikolaev Institute of Inorganic Chemistry
Dalton Transactions | Year: 2012

Depending on the synthetic conditions, five heterometallic Mn IIIFe II polynuclear compounds with the same ratio of constituents, 2[Mn(acacen)] +/[Fe(CN) 5NO] 2-, of different nuclearity and dimensionality (0D, 1D, 2D) were isolated. A [Mn(acacen)MeOH] 2[Fe(CN) 5NO]·1.5MeOH, 1 complex has been prepared by reaction of Mn III/Schiff base (SB) complex, [Mn(acacen)Cl] (H 2acacen is N,N′- ethylenebis(acetylacetoneimine)) with sodium nitroprusside (NP). Single crystal X-ray diffraction analyses reveal that crystallization of 1 from coordinating or non-coordinating solvents results in different coordination polynuclear materials: from C 2H 5OH [{Mn(acacen)H 2O} 2Fe(CN) 5NO]·C 2H 5OH, 2, a trinuclear complex is formed; from CH 3CN [{Mn(acacen)H 2O} 4Fe(CN) 5NO][Fe(CN) 5NO] ·4CH 3CN, an ionic compound with a pentanuclear bimetallic cation is formed 3; from i-C 3H 7OH [{Mn(acacen)} 2(i-PrOH)Fe(CN) 5NO] n, a coordination chain polymer 4 is formed; from toluene [{Mn(acacen)} 2Fe(CN) 5NO] n, a layered network 5 is formed. As the magnetic measurements show, for all compounds the weak interaction between Mn IIIS = 2 spins through the NP bridge is antiferromagnetic and exhibits no significant photoactivity. © The Royal Society of Chemistry 2012.

Fainer N.I.,RAS Nikolaev Institute of Inorganic Chemistry
Russian Journal of General Chemistry | Year: 2012

Films of silicon carbonitride of variable composition are prepared by the method of plasmochemical decomposition of tetramethyldisilazane, hexamethyldisilazane, and hexamethylcyclotrisilazane in the mixture with helium in the temperature range of 373-973 K. The chemical composition of the low temperature films (373-673 K) is described by the formula SiC xN yO z:H, whereas that of high temperature films, by the formula SiC xN y. The films of silicon carbonitride are found to be a nanocomposite material containing an amorphous part and nanocrystals, whose structure is close to the phase α-Si 3N 4. Films of the composition SiC xN yO z:H are promising as low-k interlayer dielectrics in ultra-large scale integrated circuits of new generation, as well as protecting antireflective coatings and light-emitting diodes. © 2012 Pleiades Publishing, Ltd.

Agency: European Commission | Branch: FP7 | Program: MC-IIFR | Phase: FP7-PEOPLE-2011-IIF | Award Amount: 15.00K | Year: 2014

The finding some polynuclear complexes can behave like magnets on the molecular level attracted much attention, opening perspectives for their applications in processing devices or for high density information storage carriers. To manifest single-molecule magnet (SMM) behaviour a polynuclear complex should have a high-spin ground-state and strong negative anisotropy (D). The energy barrier, U, separating two spin orientations (up-down) is proportional to the product of D and square of spin, S. Therefore the larger the D and S values are the higher the U barriers should be and the longer the magnetization might be blocked. However, such single-molecule magnetization is so far only observed at temperatures too low to allow an application. The project aims to rise the blocking temperature by increasing the U. Our approach is based on heterospin polynuclear complexes assembling involving orbitally-degenerated 4d, 5d metal centres (Os, Ru) and 3d metal ions or/and nitroxide radicals. If the utilisation of the first guaranties the strong anisotropy, the use of the stable radicals as ligands and bridges assures well isolated high spin ground-state owing to the strong exchange interactions between spin carriers. The synthesis work will be complemented with structural analysis and magnetic studies of these systems to elucidate the magnetic interactions as well the magnetic anisotropy in conjunction with theoretical magneto-structural analysis. A major goal of the project is to discover some rules for the rational design of polynuclear cluster systems with elevated blocking temperatures. The project results will document the coordination chemistry of 4d and 5d ions with nitroxides, a field lacking of fundamental results. The complexes will bring experimental opportunity to test and improve theoretical models. The project might be considered as a step toward molecular spintronics. Prototypes of devices could be envisioned if the right property shows up at liquid nitrogen.

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