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1.
S. P. Gromov E. N. Ushakov O. A. Fedorova A. V. Buevich M. V. Alfimov 《Russian Chemical Bulletin》1996,45(3):564-572
The stoichiometry of complexation of crown ether styryl dyes with Mg2+, Ca2+, and Ba2+ ions and the dependence of the stability constants of these complexes on the length of theN-sulfoalkyl substituent were investigated. Introduction of a terminal sulfo group into theN-ethyl substituent had but a small effect on the stability constant for the complexes with 1 : I stoichiometry. Increase in the length of theN-substituent by one or two methylene groups resulted in a jumpwise rise of this constant. The effect observed was attributed to the formation of the intramolecular ion pair. The dimerization constant for Mg2+ complexes increased dramatically when passing from the sulfopropylN-substituent to the sulfobutyl one. The increase in the constant results from the decrease in steric strains in the dimeric complex.For Part 16, see Ref. ITranslated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 605–613, March, 1996. 相似文献
2.
A. Ya. Freidzon I. I. Baskin A. A. Bagatur'yants S. P. Gromov M. V. Alfimov 《Russian Chemical Bulletin》1998,47(11):2117-2123
Regio- and stereoselectivity of [2+2]-photocycloaddition in complexes containing crown ether styryl dyes and alkaline-earth
metal cations were studied using molecular mechanics. The main assumption is that the rate of the allowed concerted photocycloaddition
correlates with the relative energies of the ground states of dimeric adducts, which are treated as pre-reaction complexes,
and the resulting cyclobutanes. These energies are estimated by molecular mechanics within the MMX parameterization. The calculated
characteristics of different dyes are studied as functions of the structure of the heterocyclic moiety, the structure and
size of the N-substituent, the size of the crown ether cycle, and the nature of the metal cation. A comparison between the
computational results and the experimental data showed that the observed quantum yield of the reaction is governed by the
relative energies of the dimeric complexes and the resulting cyclobutanes as well as by the mutual arrangement of dye molecules
in the dimeric complexes. Both factors are closely interrelated. The approach used in this work furnishes an explanation for
the experimental data and provides a guideline for supramolecular control of regio- and stereochemistry of cation-dependent
[2+2]-photocycloaddition.
For Part 24, sec Ref. 1.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2185–2191, November, 1998. 相似文献
3.
S. P. Gromov O. A. Fedorova A. I. Vedernikov Yu. V. Fedorov M. V. Alfimov 《Russian Chemical Bulletin》1997,46(5):959-966
Novel crown-containing styryl dyes (CSD) based on 15-crown-5-substituted benzothiazole with various electron-donating groups
in thepara-position of the benzene ring were synthesized. Spectral and photochemical properties ofcis- andtrans-isomers of CSD and their complexes with Mg2+ ions in solutions were studied. By analysis of spectral parameters and the magnitudes and directions of the shifts of absorption
(fluorescence) maxima, the effects of substituents and complex formation on the photochromism of CSD were elucidated. Using
quantum-chemical calculations, the possibility of controlling the degree of participation of either of the two chromophores
in the long-wave electron transition by complex formation was analyzed.
For Part 19, see Ref. 1.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 999–1006, May, 1997. 相似文献
4.
The data on the molecular design, spectral properties, photochemistry and complexation of photochromic crown ethers containing
a C=C bond are described systematically and generalized. Prospects for the practical application of these compounds are considered.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp 641–665, April, 1997. 相似文献
5.
A. V. Feofanov A. I. Ianoul V. A. Oleinikov I. R. Nabiev S. P. Gromov O. A. Fedorova M. V. Alfimov 《Russian Chemical Bulletin》1995,44(12):2323-2330
The surface enhanced Raman scattering (SERS) spectra of styryl dyes containing a crown-ether group and a heteroaromatic residue with sulfoalkyl (1a) or alkyl (1b)N-substituent and of their complexes with Mg2+ cations were recorded in the 10–4–10–8 mol L–1 concentration range. A model for the interaction of compoundsla,b with a silver surface during their adsorption on an electrochemically treated electrode was suggested. Fastcis-trans relaxation of the adsorbed molecules1a,b and complexes (1a,b)Mg2+ was found. It was shown that at [1a] = 10–5 mol L–1 and moderate molar ratios (C
Mg/[1a] = 3/1 to 9/1) in acetonitrile solutions, (trans-1a)Mg2+ complexes are joined into head-to-tail type dimers. An excess of Mg2+ cations (CMg/[1a] > 100) leads to dissociation of the dimers yielding (trans-1a)(Mg2+)2 complexes. The formation of dimers from complexes (trans-1a)Mg2+ is accompanied by a substantial distortion of the planar structure oftrans-1a. This may be an important factor influencing the efficiency of photocycloaddition involving dimers of (trans-1a)Mg2+.For part 15, see Ref. 1.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2429–2436, December, 1995.The work was carried out with financial support of the Russian Foundation for Basic Research (Project No. 94-03-08760) and, to some extent, of INTAS (Grant No. 93-1829) and of the International Science Foundation (Grant No. MHAOOO). 相似文献
6.
M. V. Alfimov S. P. Gromov O. B. Stanislavskii E. N. Ushakov O. A. Fedorova 《Russian Chemical Bulletin》1993,42(8):1385-1389
Styryl dyes containing a crown ether group and a heteroaromatic moiety with a sulfoalkylN-substituent (1a,b) undergo photocyclodimerization in acetonitrile in the presence of Mg(ClO4)2 to give only the typeA isomer of cyclobutane derivative (2a,b). The photochemical regio- and stereoselectivity of the cycloaddition is explained by self-organization of thetrans-isomers of the styryl dyes upon complexation with the Mg2+ cations into dimers with a fixed mutual arrangement of multiple bonds.For part 7, see ref. 1.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1449–1452, August, 1993. 相似文献
7.
S. P. Gromov O. A. Fedorova E. N. Ushakov A. V. Buevich M. V. Alfimov 《Russian Chemical Bulletin》1995,44(11):2131-2136
Styryl dyes (4a,b) containing a 15-crown-5 fragment and isomeric 2- and 4-quinolinium residues with anN-sulfopropyl substituent undergo [2+2]-autophotocycloaddition to give cyclobutane derivatives (9a,b) in acetonitrile only in the presence of Mg(ClO4)2 or Ca(ClO4)2. The stereospecificity of both pathways of photocycloaddition and its efficiency are explained by the preorganization of the supramolecular dimers derived from thetrans-isomers of the dyes when they are bound into complexes with Mg and Ca cations.For Part 14, see Ref. 1.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2225–2230, November, 1995.The work was carried out with financial support from the Russian Foundation for Basic Research (Project code 94-03-08531) and the International Science Foundation (Grants ISF, M8Q000 and N38000). 相似文献
8.
E. V. Tulyakova O. A. Fedorova Yu. V. Fedorov G. Jonusauskas A. V. Anisimov 《Russian Chemical Bulletin》2007,56(11):2166-2174
Using 1H NMR spectroscopy and steady-state and time-resolved electronic spectroscopy, the optical properties of mono-and bis(styryl)pyridinium
perchlorates and their complexes with Mg2+, Ba2+ cations were studied. The stability constants of the complexes were determined using spectrophotometric titration. The formation
of inclusion complexes for Mg2+ and sandwich type complexes for Ba2+ results in fluorescence enhancement and increases the lifetimes of the excited states of the initial bis-styryl ligands.
The variation of position of the styryl fragment in the pyridinium aromatic ring gives rise to photochromic crown ethers with
different optical and photophysical characteristics and is also an easy route to bis(crown-ethers) of symmetrical and unsymmetrical
structure.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2092–2100, November, 2007. 相似文献
9.
E. V. Tulyakova O. A. Fedorova Yu. V. Fedorov G. Jonusauskas L. G. Kuz’mina J. A. K. Howard A. V. Anisimov 《Russian Chemical Bulletin》2007,56(3):513-526
New styryl dyes containing azadithia-15-crown-5 fragments were synthesized. The complexation of these compounds with Ag+, Pb2+, Cu2+, Hg2+, and H+ cations was studied by 1H NMR spectroscopy, steady-state, and time-resolved spectroscopy. The stability constants of the complexes were calculated
from the spectrophotometric titration data. The photophysical properties and E—Z photoisomerization of styryl dyes and their complexes with mercury and copper(II) cations in acetonitrile were examined.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 495–507, March, 2007.
Centre de Physique Moléculaire Optique et Hertzienne-UMR CNRS 5798, Bordeaux University I, 351 Cours de la Libération, 33405
Talence, France. 相似文献
10.
A series of novel (oligo)thienyl-imidazo-benzocrown ethers were synthesised through a simple method and evaluated as fluorimetric chemosensors for transition metal cations. Interaction with Ni2+, Pd2+, and Hg2+ in ACN/DMSO solution (99:1) was studied by absorption and emission spectroscopy. Chemoselectivity studies in the presence of Na+ were also carried out and a fluorescence enhancement upon chelation (CHEF) effect was observed following Hg2+ complexation. Considering that most systems using fluorescence spectroscopy for detecting Hg2+ are based on the complexation enhancement of the fluorescence quenching (CHEQ) effect, the present work represents one of the few examples for sensing of Hg2+ based on a CHEF effect. 相似文献
11.
E. V. Tulyakova E. V. Rakhmanov E. V. Lukovskaya O. A. Fedorova A. A. Abramov A. V. Khoroshutin A. A. Bobylyova A. V. Anisimov 《Chemistry of Heterocyclic Compounds》2006,42(2):206-215
Various methods of synthesizing functional derivatives of dithia-13(16)-crown-4(5) ethers are proposed. Complex-formation
of the obtained compounds with Ag+ and Pb2+ ions has been studied using 1H NMR. A radiometric method was used to investigate the extracting ability of substituted dithia-13(16)-crown-4(5) ethers
in relation to Ag+ and Cd2+ ions from aqueous solution in the presence of anions of various degree of hardness, with determination of the metal content.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 233–243, February, 2006. 相似文献
12.
A. I. Vedernikov L. G. Kuz’mina S. K. Sazonov N. A. Lobova P. S. Loginov A. V. Churakov Yu. A. Strelenko J. A. K. Howard M. V. Alfimov S. P. Gromov 《Russian Chemical Bulletin》2007,56(9):1860-1883
New styryl dyes of the pyridine and benzothiazole series were synthesized with the aim of investigating the solid-state [2+2]
autophotocycloaddition (PCA) reaction. The 1H NMR spectroscopy showed that for most of the compounds under study, the visible light irradiation of thin polycrystalline
films of the dyes affords cyclobutane derivatives. The rate of the photoreaction depends on the structure of the dye and is
higher for compounds, which contain a short N-substituent in the heterocyclic moiety and have strong absorption in the visible region. Dyes bearing electron-releasing
substituents in the benzene ring undergo the stereospecific PCA in the syn-head-to-tail dimeric pair to give the only rctt isomer of cyclobutane derivatives. Electron-withdrawing and bulky substituents in the benzene fragment of styryl dyes extend
the range of the mutual orientations of the molecules in the dimeric pairs, resulting in the formation of two or even four
isomeric cyclobutanes in the PCA reactions. The structures of some dyes were established by X-ray diffraction. In the overwhelming
majority of the structures, one of two packing modes, either syn-head-to-tail or syn-head-to-head, with extensive stacking interactions is observed. A rare example of the anti-head-to-head stacking mode was found for the dicationic dye containing the bulky N+(Et)Me2 substituent in the benzene ring. The syn-head-to-tail and anti-head-to-head stacking modes can facilitate the PCA reaction due to the close spatial proximity of the ethylenic bonds and
their parallel orientation in the dimeric pairs of the dye molecules.
Dedicated to Academician G. A. Abakumov on the occasion of his 70th birthday.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1797–1819, September, 2007. 相似文献
13.
N. A. Rezekina E. V. Rakhmanov E. V. Lukovskaya A. A. Bobylyova A. A. Abramov V. A. Chertkov A. V. Khoroshutin A. V. Anisimov 《Chemistry of Heterocyclic Compounds》2006,42(2):216-220
8-Benzyl-1.4-dioxa-7,10-dithiacyclododecane and 11-benzyl-1,4,7-trioxa-10,13-dithiacyclopentadecane were obtained by the interaction
of (2,3-dibromo-1-propyl)benzene with 1,8-dimercapto-3,6-dioxaoctane and 1,11-dimercapto-3,6,9-trioxaundecane. The extracting
ability of the obtained compounds has been studied in relation to Sr2+ and Pb2+ ions from aqueous solutions in the presence of anions of various degrees of hardness with determination of the metal content
by a radiometric method.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 244–249, February, 2006. 相似文献
14.
Liudmil Antonov Maria Vladimirova Elena Stanoeva Walter M.F. Fabian Loreto Ballester Mariana Mitewa 《Journal of inclusion phenomena and macrocyclic chemistry》2001,40(1-2):23-28
The complexation of a series of new Schiff bases containing theN-phenylaza-15-crown-5 (Ph-A15C5) moiety with alkali and alkaline-earth metal ions (incl. Be2+ and Mg2+, is studied by means of UV-Vis spectroscopy. The corresponding stability constant values are determined and discussed from two aspects: the position of the Ph-A15C5 moiety in the ligand molecule and the nature of the metal ion. 相似文献
15.
A. M. Alstanei C. Bendic M. Carles J. P. Aycard 《Journal of inclusion phenomena and macrocyclic chemistry》2000,37(1-4):423-440
13C NMR spectroscopy was used to study thecomplexation reaction between sodium ion and12-crown-4, 15-crown-5, methylurazolyl-12-crown-4 andmethylurazolyl-15-crown-5 in CD3OD solutions. Thetype of complexes, the stability constants and therelative chemical shifts have been established byfitting experimental titration curves with theoreticalfunctions of the observed chemical shifts. Thesingle-crystal X-ray diffraction measurements for anew crystalline complex confirmed the stoichiometry ofthe complex. 相似文献
16.
Gh. H. Rounaghi A. Soleamani K. R. Sanavi 《Journal of inclusion phenomena and macrocyclic chemistry》2007,58(1-2):43-48
The complexation reactions between Ag+, Hg2+ and Pb2+ metal cations with aza-18-crown-6 (A18C6) were studied in dimethylsulfoxide (DMSO)–water (H2O) binary mixtures at different temperatures using the conductometric method. The conductance data show that the stoichiometry
of the complexes in most cases is 1:1(ML), but in some cases 1:2 (ML2) complexes are formed in solutions. A non-linear behaviour was observed for the variation of log K
f of the complexes vs. the composition of the binary mixed solvents. Selectivity of A18C6 for Ag+, Hg2+ and Pb2+ cations is sensitive to the solvent composition and in some cases and in certain compositions of the mixed solvent systems,
the selectivity order is changed. The values of thermodynamic parameters (ΔH
co, ΔS
co) for formation of A18C6–Ag+, A18C6–Hg2+ and A18C6–Pb2+ complexes in DMSO–H2O binary systems were obtained from temperature dependence of stability constants and the results show that the thermodynamics
of complexation reactions is affected by the nature and composition of the mixed solvents. 相似文献
17.
A new 1,8-naphthalimide derivative bearing an aza-15-crown-5 macrocycle (1) has been synthesized as a chemosensor for Hg2+ by a two-step reaction. The sensor shows selectivity to Hg2+ over 11 other metal cations in aqueous media. Upon addition of Hg2+, the fluorescence emission of the sensor at 537 nm is significantly quenched along with 22 nm blue-shift that makes this compound a useful sensor for Hg2+ measurement. 相似文献
18.
Bis(pyrene) derivative of diazatetrathia-crown ether has been prepared and its Hg2+-selective fluoroionophoric properties were investigated. The compound showed a pronounced Hg2+-selectivity and other metal ions except for Cu2+ showed almost no discernible responses. The Hg2+-selectivity of the compound was also confirmed by the competitive experiments performed in the presence of physiologically important metal ions and the detection limit was found to be 1.6 × 10−6 M. The prominent selective and efficient fluorescence quenching behavior could be utilized as a new chemosensing system for the analysis of toxic Hg2+ ions in aqueous environment. 相似文献
19.
An efficient synthesis and structural aspects of a novel class of hexakis(alkylseleno)benzenes [(RSeCH2)6C6] (R = Me, iPr, nBu, sBu, tBu, nPn, nHx, nOct, 1-methylnaphthalene) by the reaction of hexakis(bromomethyl)benzene with RSe− ions is demonstrated. Preliminary data on ion-sensing properties reveal that these species may act as selective ionophores for Hg2+ ions. 相似文献
20.
A simple epoxy-based oligomer 1 containing naphthylazobenzene-appended dithia-aza moieties was prepared. In UV–vis measurements, the proposed oligomer showed the ion-sensing ability to Hg2+ and Cu2+ ions. The discrimination between two differently responding Hg2+ and Cu2+ ions was also realised from ‘ON–OFF’ type fluorescence responses of 1. 相似文献