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81.
A. A. Sinelshchikova Yu. G. Gorbunova L. A. Lapkina N. Yu. Konstantinov A. Yu. Tsivadze 《Russian Journal of Inorganic Chemistry》2011,56(9):1370-1379
Erbium mono-, bis-, and tris(phthalocyaninates) with tetra-15-crown-5-phthalocyanine (H2R4Pc) were synthesized and studied by spectroscopic methods. The complexes were obtained by reacting H2R4Pc with erbium salts in high-boiling solvents. To compare the efficiency of two approaches to the synthesis of double-decker
lanthanide phthalocyaninates, bis(phthalocyaninate) [Er(R4Pc)2] was also obtained by a template procedure from dicyanobenzo-15-crown-5. A combination of physicochemical methods (UV and
IR spectroscopy, MALDI-TOF mass spectrometry, 1H NMR) was used for identifying the compounds and proving their individuality and structure. The photoluminescence method
demonstrated that solutions of erbium bis- and tris(phthalocyaninates) in CHCl3 are nonfluorescent in the visible range of light whereas solutions of mono(phthalocyaninate) in CHCl3 and DMSO exhibit fluorescence with maxima at 707 and 695 nm, respectively. The oxidation of erbium mono(phthalocyaninate)
leads to fluorescence quenching. 相似文献
82.
S. L. Selektor A. V. Shokurov O. A. Raitman L. S. Sheinina V. V. Arslanov K. P. Birin Yu. G. Gorbunova A. Yu. Tsivadze 《Colloid Journal》2012,74(3):334-345
The spectral, electrochemical, and optical properties of Langmuir-Blodgett films (LBFs) and cast films from a solution of new double-decker cerium bis[tetra-(15-crown-5)-phthalocyaninate] (Ce(R4Pc)2) are studied. Based on analysis of compression isotherms and quantum-chemical calculations, schemes of the organization of Ce(R4Pc)2 molecules at different states of its monolayers are proposed. Correlation dependences are determined in order to relate the optical and electrochemical characteristics of monolayers and LBFs of sandwich-type lanthanide phthalocyaninates to the ionic radii of their metal centers. The valent state of Ce ions in a monolayer-forming complex is determined, and a sequence of redox transformations occurring in LBF uppon appliance of a potential is proposed, one of the transformations being associated with the Ce3+/Ce4+ redox transition. Orientation-induced intramolecular electron transfer is revealed in the planar supramolecular system. It is shown that, during the formation of a monolayer from a Ce(R4Pc)2 solution, a tetravalent metal center passes to a trivalent state. Monolayer compression to a high surface pressure reverts the complex to the electronic state typical of the solution. The reversible transformations observed upon the monolayer compression result from intramolecular electron transfer from the 4f-orbital of Ce to the phthalocyanine ring and backwards. The high operation rate and the reversibility of switching between the stable states, which are determined by means of the surface plasmon resonance technique, upon a stepwise change in the electrode potential within the range of 200?C850 mV may underlie the development of optoelectronic systems. With a large number of molecules in a stacking aggregate, changes in the distance between the decks of the complex that occur with changes in the oxidation level of the metal center can substantially modulate the sizes of molecular ensembles. A supramolecular device capable of performing mechanical work can be developed based on this effect. 相似文献
83.
Alexander V. Shokurov Daria S. Kutsybala Andrey P. Kroitor Alexander A. Dmitrienko Alexander G. Martynov Yulia Yu. Enakieva Aslan Yu. Tsivadze Sofiya L. Selektor Yulia G. Gorbunova 《Molecules (Basel, Switzerland)》2021,26(14)
Coordination-induced spin crossover (CISCO) in nickel(II) porphyrinates is an intriguing phenomenon that is interesting from both fundamental and practical standpoints. However, in most cases, realization of this effect requires extensive synthetic protocols or extreme concentrations of extra-ligands. Herein we show that CISCO effect can be prompted for the commonly available nickel(II) tetraphenylporphyrinate, NiTPP, upon deposition of this complex at the air/water interface together with a ruthenium(II) phthalocyaninate, CRPcRu(pyz)2, bearing two axial pyrazine ligands. The latter was used as a molecular guiderail to align Ni···Ru···Ni metal centers for pyrazine coordination upon lateral compression of the system, which helps bring the two macrocycles closer together and forces the formation of Ni–pyz bonds. The fact of Ni(II) porphyrinate switching from low- to high-spin state upon acquiring additional ligands can be conveniently observed in situ via reflection-absorption UV-vis spectroscopy. The reversible nature of this interaction allows for dissociation of Ni–pyz bonds, and thus, change of nickel cation spin state, upon expansion of the monolayer. 相似文献
84.
The nature of paramagnetic centers in a nanostructure based on single-walled carbon nanotubes (SWCNTs) encapsulated with Pd was studied by EPR spectroscopy at 77 and 293 K. It was found that strong charge-transfer π complexes of the (Pd-C x ) type, which manifested themselves as a narrow resonance (ΔH = 6–8 G and g = 2.002 at T = 77 k), were formed in the Pd-SWCNT composite along with impurity centers (Fe3O4 nanoparticles within the nanotubes), which were responsible for a broad EPR signal (ΔH = 75 G and g = 2.065 at T = 293 K). These complexes were found to be predominant adsorption sites responsible for a high gravimetric density of hydrogen (H/C ≥ 1.0) within the single-walled carbon nanotubes. 相似文献
85.
A. Ya. Fridman A. Yu. Tsivadze E. M. Morozova N. P. Sokolova A. M. Voloshchuk G. A. Petukhova I. I. Bardyshev A. M. Gorbunov A. K. Novikov I. Ya. Polyakova V. N. Titova A. A. Yavich N. V. Petrova 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2016,90(3):641-646
A material with an electrically ОН–-conductive porous layer of cyclam-substituted PVC filled with active coal containing NaOH aqua complexes with aza-crown ligands and cross-linked with the surface of cellulose tissue fibers has been synthesized. The structure of the material was studied. Its sorption capacity in vapors and liquid benzene and hexane, specific resistance, potential of ОН- transfer from solution to layer, and rate constants of ОН– travel in the layer of the material as an electrochemical bridge in vapors and liquid benzene and hexane were determined. The aqua complexes decomposed in the layer with formation of Н2 during the cathodic polarization of the bridge and О2 during the anodic polarization; the composition of the complexes was regenerated due to the motion of ОН–. 相似文献
86.
87.
88.
V. I. Dvorkin Yu. G. Gorbunova V. I. Zhilov G. Yu. Sitnikova A. Yu. Tsivadze 《Journal of Analytical Chemistry》2002,57(6):552-556
It is shown that potassium and sodium simultaneously present in aqueous solutions can be determined by photometry with the use of tetra-15-crown-5-phthalocyaninatocobalt. 相似文献
89.
N. O. Mchedlov-Petrosyan Yu. N. Surov V. A. Trofimov A. Yu. Tsivadze 《Theoretical and Experimental Chemistry》1991,26(6):644-653
A combined analysis of two types of vibrational spectra (Raman and infrared) has proven the lactone structure of colorless solid preparations of phenolphthalein and thymolphthalein. It has been shown that phenolsulfophthalein, its alkyl derivatives, and bromcresol purple exist in the solid state primarily in the form of an intensely colored zwitterion; bromphenol blue and bromthymol blue exist primarily in the form of a colorless sultone. For the ionized forms of triphenylmethane dyes (cationic and anionic chromophore systems) vibrations with a frequency near 1360 cm–1 are characteristic in the IR spectra and also in the Raman spectra.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 26, No. 6, pp. 688–698, November–December, 1990. 相似文献
90.