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Andrianov V.M.,B. I. Stepanov Institute of Physics | Korolevich M.V.,Belarusian State Agrarian Technical University
Journal of Applied Spectroscopy | Year: 2015

Normal vibrational frequencies and absolute IR band intensities of the biologically active steroid phytohormones homobrassinolide and (22S,23S)-homobrassinolide were calculated in the framework of an original approach that combined classical analysis of normal modes using molecular mechanics with quantum-chemical estimation of the absolute intensities. IR absorption bands were interpreted based on a comparison of the experimental and theoretical absorption spectra. The impact of structural differences in the side chains of these molecules on the formation of their IR spectra in the region 1500–950 cm−1was estimated. © 2015 Springer Science+Business Media New York


Crepin C.,CNRS Orsay Institute for Molecular Science | Shafizadeh N.,CNRS Orsay Institute for Molecular Science | Chin W.,CNRS Orsay Institute for Molecular Science | Galaup J.-P.,University Paris - Sud | And 2 more authors.
Low Temperature Physics | Year: 2010

An unexpected phenomenon was revealed in the laser induced fluorescence spectra of free-base (H2Pc) and zinc (ZnPc) phthalocyanines trapped in rare gas and nitrogen matrices under a moderate increase in the laser intensity. In all matrices the intensity of an emission band near 755nm increased drastically when pumping the S1←S0 transition. This observation was assigned to stimulated emission in a four-level scheme involving a vibronic transition from the lowest electronic state to a vibrational level of the ground state. In the present work, we expose new similar results obtained with porphyrin molecules, i.e. tetra-benzoporphin (TBP). With free-base H2TBP, stimulated emission was observed in Ar or N2 matrices, but not in Xe matrices. A possible reason could be a fast inter-system crossing rate due to the heavy atom effect induced by Xe. We also report the observation of persistent burnt spectral holes, although the low efficiency of this process is not competitive with stimulated emission and no decrease of the stimulated emission with time was observed. With ZnTBP no stimulated emission could be recorded but the appearance of rather strong phosphorescence was noticed. Similar studies focusing on the stimulated emission phenomenon is that they should allow new insights into site effects and site selectivity. © 2010 American Institute of Physics.


Arabei S.M.,Belarusian State Agrarian Technical University | Pavich T.A.,B. I. Stepanov Institute of Physics | Solovyov K.N.,B. I. Stepanov Institute of Physics
Journal of Porphyrins and Phthalocyanines | Year: 2013

In this mini-review, we present the main results of our works on the spectroscopy of the molecules of tetrapyrrole pigments incorporated into nanoporous gel matrices. Xerogels activated by organic dyes are promising materials for applications in various fields of technology. The influence of the technique of embedment of the activator molecules on their physico-chemical properties has been analyzed. The specificity of the action of a silicate matrix as external medium, as compared to liquid and solid solutions, is shown. © 2013 World Scientific Publishing Company.


Arabei S.,Belarusian State Agrarian Technical University | McCaffrey J.G.,National University of Ireland | Galaup J.-P.,University Paris - Sud | Shafizadeh N.,CNRS Orsay Institute for Molecular Science | Crepin C.,CNRS Orsay Institute for Molecular Science
Physical Chemistry Chemical Physics | Year: 2015

Thin cryogenic samples of inert gas solids doped with free-base tetraazaporphine (H2TAP) were irradiated with a tunable pulsed laser. Under resonant electronic excitation of the guest, specific vibronic transitions of the fluorescence spectra were found to be strongly enhanced with only a moderate increase of the laser power. This enhancement is due to stimulated emission (SE). The characteristics of SE bands are described in the three hosts (Ar, N2, and Ne) explored, as well as their excitation spectra. SE is observed in transitions involving different vibrational modes of the guest, depending on the host and the electronic excitation. The results are discussed in comparison with previous works on other tetrapyrrolic molecules trapped in inert gas matrices. From this comparison the key features required to observe SE are deduced to be: (1) SE can be obtained with various tetrapyrrolic molecules; (2) free-base molecules are preferable to their metallo-counterparts; (3) the results highlight a specific molecular vibrational mode involved in the process; and (4) cryogenic crystal structures are also of importance in the detection of SE. © the Owner Societies 2015.


Arabei S.M.,Belarusian State Agrarian Technical University | Galaup J.-P.,University Paris - Sud | McCaffrey J.G.,National University of Ireland, Maynooth | Shafizadeh N.,CNRS Orsay Institute for Molecular Science | Crepin C.,CNRS Orsay Institute for Molecular Science
Low Temperature Physics | Year: 2012

This paper deals with our on-going work on the electronic spectroscopy of tetrapyrrole molecules embedded in cryogenic hosts. Under nanosecond laser excitation of free-base tetrabenzoporphin molecules in a nitrogen matrix at 8 K, increasing laser pulse energy results in essential enhancement of the intensity of one or several vibronic emission lines in the fine-structure fluorescence spectrum. Some characteristics of stimulated radiation are realized in the observed intense monochromatic radiation as a result of a transition from the purely electronic S1 level to a vibrational sublevel of the S0 state, corresponding to the excitation of C-C stretching vibrations of tetrapyrrole methane bridges. We also report on persistent spectral hole-burning effects. Hole and antihole formation analysis gives some insight on the photochemical properties of tetrabenzoporphin in a nitrogen matrix. © 2012 American Institute of Physics.


Dyachkova L.N.,National Academy of Sciences of Belarus | Leonov A.N.,Belarusian State Agrarian Technical University | Vityaz P.A.,National Academy of Sciences of Belarus
Euro PM 2014 Congress and Exhibition, Proceedings | Year: 2014

The process of infiltration of porous skeleton based on iron by copper alloys and the conse-quent isothermal holding allow forming the structure and properties which provide specific characteris-tics of iron-copper material; due to this fact, they are widely applied in the production of antifriction ap-plication. The formation of the structure and properties of iron-copper pseudoalloys depend on the pa-rameters of iron skeleton and infiltrant, which affect the process of infiltration, and the isothermal time after the infiltration. Redistribution of the alloying elements in the iron skeleton with the formation of composite structure occurs in the process of isothermal holding.


Troyanchuk I.O.,National Academy of Sciences of Belarus | Bushinsky M.V.,National Academy of Sciences of Belarus | Dobryanskii V.M.,Belarusian State Agrarian Technical University | Pushkarev N.V.,International Sakharov Environmental University
JETP Letters | Year: 2011

In layered Sr 3YCo 4O 10.5 + δ-type cobaltites with different oxygen contents, we have observed a first order magnetic phase transition from the high-temperature "ferromagnetic" state to the low-temperature antiferromagnetic state. The transition can be induced by an applied magnetic field. It is accompanied by a significant hysteresis in the magnetic field (~10 T) and temperature (~10 K). A decrease and an increase in the yttrium content lead to a purely "ferromagnetic" and antiferromagnetic behavior, respectively. © 2011 Pleiades Publishing, Ltd.


Babkov L.M.,Chernyshevsky Saratov State University | Ivlieva I.V.,Chernyshevsky Saratov State University | Korolevich M.V.,Belarusian State Agrarian Technical University
Journal of Applied Spectroscopy | Year: 2015

The structures of isolated 2,3-di-O-nitromethyl-β-D-glucopyranoside and its H-bonded complexes were modeled using density functional method B3LYP/6-31G(d). Their IR spectra were calculated in the harmonic approximation. It was concluded based on the modeling results that the H-bond affected the structure and IR spectrum of 2,3-di-Onitromethyl-β-D-glucopyranoside. The IR spectrum measured in the range 600–3700 cm–1 at room temperature was interpreted. © 2015 Springer Science+Business Media New York


Grant
Agency: Cordis | Branch: FP7 | Program: CSA-SA | Phase: INCO.2013-9.1 | Award Amount: 1.18M | Year: 2013

NoGAP bridges the gap between research and innovation and contributes to taking advantage of the innovation potential of SMEs based on a better cooperation with researchers, transferring and using knowledge resulting from research. The overall objective of the project is to reinforce cooperation with Eastern Partnership countries to develop a Common Knowledge and Innovation Space on societal challenge secure, clean and efficient energy. The NoGAP consortium is composed of 13 organizations from 6 countries of which 3 are EU members (Germany, Romania, Slovakia) and 3 are members of the Eastern Partnership (Belarus, Ukraine, Georgia). In order to improve mobility between research, business and innovation, interrelated tandem relations between research organizations and innovation support services are established. Within the NoGAP project we want to: - identify the main drivers and obstacles of closer links between academia and the market in the field of secure, clean and efficient energy in the Eastern Partnership Region - develop a best practice methodology to enhance successful commercialization of research results and to improve the management of these results - develop innovation support services to foster existing and establish new strategic partnerships - assess the opportunities for the establishment of sustainable Technology Transfer Centres (TTC) in the participating partner countries on the basis of existing structures and good practice - improve the competencies of researchers, entrepreneurs and multiplicators by organizing trainings - develop a list of pilot activities to foster mutually beneficial public-private-partnerships between EU and Eastern Partnership countries in the energy sector - create and organize twinnings between the regions - promote networking between EU and Eastern Partnership countries.


Stanishevsky I.V.,Belarusian State Agrarian Technical University | Chernyavskii V.A.,Belarusian State Agrarian Technical University
Journal of Applied Spectroscopy | Year: 2015

The fluorescence polarization kinetics of fluorescent organic molecules and molecules with two interconverting photoisomeric forms and fixed molecular skeletons were investigated by numerical methods based on the solution of population balance equations. The depolarizing effect of the lowest triplet T1 state and the polarization time dependence for quasi-continuous-wave (cw) and pulsed photoexcitation were studied using model compounds. The fluorescence depolarization with cw excitation was characterized by times that were shorter than the T1-state lifetime; for the isomers, also by times that correlated with the photoisomerization times. Intense pulsed photoexcitation distorted significantly the initial oscillator orientation distribution in the singlet S0 and S1 states and could lead to sign reversal of the polarization. © 2015, Springer Science+Business Media New York.

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