Logo of NIIC SB RAS

Nikolaev Institute of Inorganic Chemistry

Siberian Branch of Russian Academy of Sciences

SELECTED RESULTS OF COMPLETED RESEARCH STUDIES in 2010

Chemistry of inorganic compounds including coordination, cluster, and supramolecular compounds

Red-NIR luminescent hybrid poly(methyl methacrylate) containing covalently linked octahedral rhenium metallic clusters

Scheme of the preparation of the {Re6}-doped
PMMA hybrid material

Scheme of the preparation of the {Re6}-doped
PMMA hybrid material

The anionic complex [Re6Sei8(OH)a6]4– was primarily functionalized in two steps with tert-butylpyridine (TBP) and methacrylic acid (HMAC) to give neutral cluster building block [Re6Sei8(TBP)a4(MAC)a2] that was copolymerized with methylmethacrylate (MMA). Several samples containing 0.025, 0.05 and 0.1 wt% of the functionalized {Re6} clusters were prepared. All the samples show a bright (absolute emission quantum yield ~ 0.07), broad and structureless emission band, which extends from ~ 600 nm to more than 950 nm, with the maximum wavelength centered around λem = 710 nm. It is worth noting that this value is one of the highest photoluminescence quantum yields reported so far for red-NIR luminescent polymers doped with inorganic compounds. Moreover, the high stability of the incorporated inorganic phosphors prevents the material from photobleaching, and thus the luminescence properties are kept entirely even after nine months of ageing.

Molard Y., Dorson F., Brylev K.A., Shestopalov M.A., Le Gal Y., Cordier S., Mironov Y.V., Kitamura N., Perrin C. «Red-NIR Luminescent Hybrid Poly(methyl methacrylate) Containing Covalently Linked Octahedral Rhenium Metallic Clusters» Chem.-Eur. J. 2010. V. 16. P. 5613.

Emission spectra obtained for pure PMMA and copolymers [Re6Se8(TBP)4(MAC)2]@PMMA with the different content of the cluster

Emission spectra obtained for pure PMMA and copolymers [Re6Se8(TBP)4(MAC)2]@PMMA with the different content of the cluster

Photographs of the PMMA and Re6–PMMA pellets. Top: under normal daylight; bottom: under UV irradiation. The weight percentage of clusters increases from left to right: 0, 0.025, 0.05, and 0.1 wt%, respectively

Photographs of the PMMA and Re6–PMMA pellets. Top: under normal daylight; bottom: under UV irradiation. The weight percentage of clusters increases from left to right: 0, 0.025, 0.05, and 0.1 wt%, respectively

Novel Approach to the Synthesis of Polynuclear Organometallic Compounds

Novel approach to the synthesis of polynuclear organometallic compounds containing simultaneously d-, f-metals and group 15 and 16 elements in their cores has been developed. The approach consists in reduction of polychalcogenide and polypnictide complexes of transition metals by lanthanide(II) complexes. Using the approach the first examples of polyphosphide and polychalcogenide heterometallic clusters containing both d-metal and lanthanide (Sm, Yb) (figure) have been obtained. That opens up possibilities to prepare novel precursors for a variety of chalco- and pnicogenide heterometallic phases and nano-materials possessing interesting magnetic and electroconducting properties.

[(Cp*<sub>2</sub>Yb)<sub>2</sub>Fe<sub>6</sub>S<sub>6</sub>(CO)<sub>6</sub>]

[(Cp*2Yb)2Fe6S6(CO)6]

[Cp*FeP<sub>5</sub>Sm(DIP<sub>2</sub>pyr)(THF)<sub>2</sub>]

[Cp*FeP5Sm(DIP2pyr)(THF)2]

[Cp*FeP<sub>5</sub>Sm(DIP<sub>2</sub>pyr)]<sub>2</sub>

[Cp*FeP5Sm(DIP2pyr)]2

The first examples of polyphosphide and polychalcogenide heterometallic clusters containing both d-metal and lanthanide – precursors of chalco- and pnicogenide heterometallic phases and nano-materials possessing interesting magnetic and electroconducting properties.

Konchenko S.N., Sanden T., Pushkarevsky N.A., Koppe R., Roesky P.W.Chemistry – A European Journal. 2010. DOI: 10.1002/chem.201002510

Chemical thermodynamic of inorganic systems

Structures of Tetrabutylammonium Chloride Ionic Clathrate Hydrates

Three ionic clathrate hydrates of different water content formed in (С4H9)4NCl – H2O system are synthesized and characterized by single-crystal and powder X-ray diffraction. Structural justification of occurrence of three different ionic clathrate hydrates derived from tetragonal structure-I (TS-I) has been found for the first time. A novel mode of hydrophilic inclusion of halide anion with displacement of two hydrogen-bonded host water molecules has been revealed. Structural data obtained are indicative of possibility of location of tetrabutylammonium cations in combined cavities formed with participation of small D-voids. The various ways of adjustability of the same type of clathrate hydrate framework to the guest particles are demonstrated. This gives a new interpretation of some physico-chemical properties of water – hydrate former system.

Rodionova T., Komarov V., Villevald G., Aladko L., Karpova T., Manakov A.«Calorimetric and Structural Studies of Tetrabutylammonium Chloride Ionic Clathrate Hydrates»J. Phys. Chem. B. 2010. V. 114, N 36. P. 11838-11846.

Crystal chemistry and electronic structure of inorganic compounds

Macrocyclic anion [(Mo8O28)4(Mo2O2S2)4]24–

Rare isomeric form of octamolybdate [Mo8O28]8– was isolated as part of a unique macrocyclic anion [(Mo8O28)4(Mo2O2S2)4]24–, which is built of four octamolybdate units {Mo8O28} bridged by the [Mo2O2S2]2+ thiocations. This structure contains open cavities. Stability of the macrocyclic anion in various solvents was studied. This result is important for design of new molecular containers.

Unstable {Mo<sub>8</sub>O<sub>28</sub>}<sup>8–</sup> isomer (<em>grey octahedra</em>) stabilized by coordination to the binuclear oxothiocation [Mo<sub>2</sub>O<sub>2</sub>S<sub>2</sub>]<sup>2+</sup> (<em>orange octahedra</em>) in the structure of [(Mo<sub>8</sub>O<sub>28</sub>)<sub>4</sub>(Mo<sub>2</sub>O<sub>2</sub>S<sub>2</sub>)<sub>4</sub>]<sup>24–</sup>

Unstable {Mo8O28}8– isomer (grey octahedra) stabilized by coordination to the binuclear oxothiocation [Mo2O2S2]2+ (orange octahedra) in the structure of [(Mo8O28)4(Mo2O2S2)4]24–

Korenev V.S., Boulay A.G., Dolbecq A., Sokolov M.N., Hijazi A., Floquet S., Fedin V.P., Cadot E.«A new oxomolybdate component extracted from the «virtual dynamic library» yielding the macrocyclic anion [(MoVI8O28)4(MoV2O2S2)4]24−»Inorg. Chem. 2010. V. 49. P. 9740-9742.

Physical and chemical foundation of substances separation and purification

A photometric method for determining electrokinetic potential of nano- and microparticles

A simple photometric method for determining the electrophoretic mobility of nanoparticles in reverse micelles of AOT and in solvents with a low dielectric permeability (2-5) has been developed.

Concerning known methods (PALS, LDE, etc.), used in modern devices of the foreign companies, the offered method gives the possibility to define electrophoretic mobility of nanoparticles which size is less than 5 nanometers. The method is important for characterization of ultrafine systems in liquid medium.

Photometric technique for nano - and microparticles electrokinetic potential determination: the general scheme (A) and electrophoretic cells with different electrode orientations (B, C, and D).

Photometric technique for nano - and microparticles electrokinetic potential determination: the general scheme (A) and electrophoretic cells with different electrode orientations (B, C, and D).

Bulavchenko A.I. Popovetsky P.S.«The electrokinetic potential of nanoparticles in reverse AOT micelles: photometric determination and role in the processes of heterocoagulation, separation, and concentration»Langmuir. 2010. V. 26. № 2. P. 736-742.

Stereoselective sorption of sulfoxide into porous coordination polymers based on zinc complexes

In collaboration with Tohoku University (Japan), the sorption of different guest molecules (both R- and S-isomers) into the chiral pores of [Zn2(bdc)(S-lac)(dmf)] was modeled using ab initio calculations that provided a qualitative explanation for the observed sorption enantioselectivity. The high stereopreference is accounted for by the presence of coordinated inner-pore dmf which forms a weak C−H···O bond between the dmf methyl group and the S-PhSOCH3 sulfinyl group. Investigated homochiral sorbents can be applied for chromatographic stereo selective separation of racemic mixtures of optical isomers onto different enantiomers. The fine purification of chiral bioactive molecules is a very important problem, especially for pharmaceuticals, because the nature often treats pairs of enantiomers as different compounds.

[Zn<sub>2</sub>(bdc)(<em>S</em>-lac)(dmf)]·<em>S</em>-PhSOMe, E = −1,6 kcal/mol, stable

[Zn2(bdc)(S-lac)(dmf)]·S-PhSOMe, E = −1,6 kcal/mol, stable

[Zn<sub>2</sub>(bdc)(<em>S</em>-lac)(dmf)]·<em>R</em>-PhSOMe, E = +6,8 kcal/mol, unstable

[Zn2(bdc)(S-lac)(dmf)]·R-PhSOMe, E = +6,8 kcal/mol, unstable

Presentation of the optimized chiral methyl phenyl sulfoxide guest orientations inside the pores of the [Zn2(bdc)(S-lac)(dmf)] framework.

Dybtsev D.N., Yutkin M.P., Samsonenko D.G., Fedin V.P., Nuzhdin A.L., Bezrukov A.A., Bryliakov K.P., Talsi E.P., Belosludov R.V., Mizuseki H., Kawazoe Y., Subbotin O.S., Belosludov V.R.«Modular, Homochiral, Porous Coordination Polymers: Rational Design, Enantioselective Guest Exchange Sorption and Ab Initio Calculations of Host–Guest Interactions»Chem.-Eur. J. 2010. V. 16. N 34. P. 10348-10356.

Chemistry and technology of functional materials

Preparation and properties of graphene – new carbon material

New methods for chemical modification of highly exfoliated graphite and its transfer to colloidal dispersion state and to graphene films are developed. The resulting colloid solutions and graphene films are characterized by a set of physical methods including diffraction, transmission electron and atomic force microscopy, Raman spectroscopy etc. It was shown that monolayer dispersions form graphene films with ideal hexagonal structure. The materials are promising for future nanoelectronics.

Preparation of graphene by chemical functionalization and colloidal dispersions.

Preparation of graphene by chemical functionalization and colloidal dispersions.

Lee J.H., Shin D.W., Makotchenko V.G., Nazarov A. S., Fedorov V.E., Yoo J.H., Yu S.M., Choi J.-Y., Kim J.M., Yoo J.-B.«One step exfoliation Synthesis of Easy Soluble Graphite and Transparent Conducting Graphene Sheet»Small. 2010. V. 6. P. 58-62.

High-k films as materials for nanoelectronic devices of new generation

Crystal films of monoclinic modification were obtained by CVD method at substrate temperature of 350°C using Ph2Hf(N(C2H5)2)2 as precursor. Interlayer of complex composition forms between films and Si substrate. Influence of Si substrate prior treatment in ammonia ambient was investigated. Characteristics of test Al/HfO2/Si structures were studied. The films synthesized on the substrates treated with ammonia (curve 2) show the more high value of k=15 (comparable with k for monoclinic modification HfO2, k= 16) as compared with the films obtained on non-treated Si substrate surface (k=11). Addition of oxygen in gas phase results in the films synthesis with low leakage current and its C-V characteristics does not show hysteresis (curve 1).

Micrograph of the HfO<sub>2</sub>/Si cross section

Micrograph of the HfO2/Si cross section

C-V characteristics of the Al/HfO<sub>2</sub>/Si test structure

C-V characteristics of the Al/HfO2/Si test structure

Smirnova T.P., Yakovkina L.V., Beloshapkin S.A., Kaichev V.V., Alferova N.I., Song Jeong-Hwan«Interface Analysis of the HfO2/SiO2/Si structure»J. Phys. Chem. Sol. 2010. V. 71. P. 836-840.

Independent control of the charge-carrier density and electronic anisotropy in HTSC single crystals

High quality Lu1-yCayBa2Cu3O6+x single crystals possessing a thin-plate shape suitable for Hall measurements, and exhibiting narrow superconducting transitions and low resistivity values characteristic of impurity-free crystals have been grown by the flux method. The substitution of Ca for Lu in Lu1-yCayBa2Cu3O6+x single crystals allowed us to set exactly the required density of charge carriers n (n=y/2 for x=0), which was confirmed by the measurements of the Hall resistivity and the low-temperature heat capacity, performed in collaboration with the Kirensky Institute of Physics, SB RAS. The electrical resistivity anisotropy in RBa2Cu3O6+x crystals in its turn was shown to change drastically with the oxygen concentration. A possibility therefore emerges to investigate HTSC crystals with a separate control of the two principal parameters of the electronic system: the electronic anisotropy and the density of carriers.

Lu<sub>0.8</sub>Ca<sub>0.2</sub>Ba<sub>2</sub>Cu<sub>3</sub>O<sub>6+x</sub> single crystal with attached electrical contacts

Lu0.8Ca0.2Ba2Cu3O6+x single crystal with attached electrical contacts

Enlarged view of the crystal’s cross-section exposed by breaking the sample (typical crystals’ length – 1-5 mm, thickness – 8-10 μm)

Enlarged view of the crystal’s cross-section exposed by breaking the sample (typical crystals’ length – 1-5 mm, thickness – 8-10 μm)

Dependence of the electrical resistivity anisotropy in TmBa<sub>2</sub>Cu<sub>3</sub>O<sub>6+x</sub> on temperature and oxygen concentration

Dependence of the electrical resistivity anisotropy in TmBa2Cu3O6+x on temperature and oxygen concentration

K. A Shaykhutdinov, S. I. Popkov, A. N. Lavrov, L. P. Kozeeva, M. Yu. Kameneva, V. V. Val'kov, D. M. Dzebisashvili, and A. D. Fedoseev«Features of the low-temperature specific heat in underdoped YBa2Cu3O6+x single crystals»JETP Lett. 2010, 92, 332-337.

S. G. Ovchinnikov, M. M. Korshunov, L. P. Kozeeva, and A. N. Lavrov«Peculiarity of interrelation between electronic and magnetic properties of HTSC cuprates associated with short-range antiferromagnetic order»JETP 2010, 111, 104-113.

Influence of metal phthalocyanines molecular structure in the orientation of their films

Study of the influence of molecular structure in the orientation of liquid crystalline metal phthalocyanines has been carried out. It was shown by the methods of IR and Raman spectroscopies as well as by polarizing microscopy that the films deposited on the surface of one substrate (glass, Si, Au, NaCl) are characterized by planar alignment. This type of orientation is typical for the films of discotic liquid crystals obtained with an air interface without a specific interaction between the phthalocyanine film and a substrate and it doesn’t depend on geometry of phthalocyanine molecule and type of substituents in phthalocyanine ring.

Films of azacrownsubstited phthalocyanines with homeotropic alignment relative to the substrate surface have been obtained on NaCl surface. This type of orientation may be explained by the specific interaction between the phthalocyanine molecules and NaCl surface due to ability of the pendant monoazacrown ether groups to coordinate alkali ions and trigger the homeotropic alignment of molecular columns.

Polarizing optical microscopy images of azacrown-NiPcR<sub>4</sub> film deposited on a glass slide

Polarizing optical microscopy images of azacrown-NiPcR4 film deposited on a glass slide

NiPc film deposited on NaCl substrate

NiPc film deposited on NaCl substrate

Basova T., Latteyer F., Atilla D., Gürek A.G., Hassan A., Ahsen V., Peisert H., Chassè T.«Effects of interactions with the surface on the orientation of the mesogenic monoazacrown-substituted phthalocyanine films»Thin Solid Films. 2010. V. 518(20). P. 5745-5752.

Effective KGd(WO4)2:Eu3+ crystal laser in the visible spectral region

Potassium-gadolinium tungstate laser crystals, KGd(WO4)2 : Eu3+, doped by europium of a high concentration (25 at.%), have been growing by low-gradient Czochralski method from solution in double tungstate-potassium melt. For the first time the effective generation in the visible spectral region on the rare-earth metals ions (Eu3+) was obtained on the 5D07F4 transition (703 nm wavelength), without using nonlinear conversion of laser emission. Under pulse pumping, high efficiency lasing have been demonstrated for both free running and Q-switched modes of operation. The obtained crystals are of considerable interest for design of new generation of scientific and applied lasers, including physical metrology and medicine.

The KGd(WO<sub>4</sub>)<sub>2</sub> : Eu<sup>3+</sup> crystal

The KGd(WO4)2 : Eu3+ crystal

Fluorescence spectrum

Fluorescence spectrum

Bagaev S.N., Dashkevish V.I., Orlovish V.A., Vatnik S.M., Pavlyuk A.A., Urkin A.M.Quantum Electronics 2011, 41,(3), 189 – 192.