Molecular simulation of the complexation effects on conformations and electronic absorption spectra of crown ether styryl dyes

Baskin, Igor I.; Burshtein, K. Ya.; Bagatur’yants, A. A.; Gromov, S. P.; Алфимов, М. В.

doi:10.1016/0022-2860(92)80149-c

Cited by 30 publications

(10 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We tbund that the hypsochromic shifts of the LAB of these complexes are not actually the same, but they are due to the dramatic decrease in the intensity of the cha~e-transfer band caused by the break of conjugation in the chromophore. 44 In order to estimate experimentally the extent to which the conjugation in the chromophore is violated after the formation of the anion-"capped" complexes by c/s-isomers of CSD, we compared their spectra with those obtained by the addition of the absorption spectra of the betaines derived from heterocyclic bases to the spectrum of the complex of BI5C5 with Mg 2+. In all cases, the resulting theoretical spectra reproduced qualitatively the absorption spectra of the anion~ complexes of CSD (see, for example, Fig.…”

Section: Methodsmentioning

confidence: 99%

Supramolecular organic photochemistry of crown-ether-containing styryl dyes

Gromov

Алфимов

1997

Russ Chem Bull

View full text Add to dashboard Cite

show abstract

Section: Methodsmentioning

confidence: 99%

Supramolecular organic photochemistry of crown-ether-containing styryl dyes

Gromov

Алфимов

1997

Russ Chem Bull

View full text Add to dashboard Cite

show abstract

“…Crown ether substituted dyes absorb light in the visible region of the spectrum and bind metal cations selectively. − Such compounds have been used, for example, as reagents for calorimetric or fluorimetric determination of metal cations and as components of photoswitchable molecular devices. − The supramolecular organic photochemistry of crown-containing styryl dyes (CSDs) that can undergo photoswitching is a vigorously developing field of research. − Experimental observations , and theoretical calculations indicate that, of the compounds that we have investigated, the most promising CSDs differ from trans - 1a by substitution of ω-alkylsulfonate groups for the ethyl group at the N atom of the benzothiazolium moiety. For instance, the photochromic CSDs 1b,c (Scheme ) allow control of the binding of metal cations by virtue of light because they are capable of “taking off” and “putting on” their anionic “cap” upon exposure to light of various wavelengths …”

Section: Introductionmentioning

confidence: 99%

Synthesis, Structure, and Ion Selective Complexation of Trans and Cis Isomers of Photochromic Dithia-18-crown-6 Ethers

et al. 1999

View full text Add to dashboard Cite

Photochromic styryl dyes containing benzodithia-18-crown-6 and N-substituted benzothiazolium moieties are synthesized and characterized spectroscopically and, for a specific case, by X-ray crystallography. The effects of the N-substituent and of sulfur atom substitution in the crown ether cavity on metal cation complex formation and on photochromism due to reversible trans−cis photoisomerization are evaluated. High selectivities for heavy metal ions, such as Ag+ and Hg2+, are observed, in contrast to the benzo-18-crown-6 dyes which selectively bind alkali and alkali earth cations. Relative complex formation stability constants, determined spectrophotometrically, are converted to absolute values by polarographic measurements. The stability constant for Hg2+ complex formation by the trans dye is enhanced 47-fold upon substitution of the 4-butylsulfonate group for methyl at the nitrogen of the benzothiazolium moiety. Photoisomerization to the cis dye is accompanied by a further 11-fold stability constant increase and by spectral changes that are consistent with formation of an ion-“capped” complex, involving intramolecular coordination of the sulfonate anion to Hg2+. Addition of a large excess of Mg2+ ions disrupts this intramolecular coordination bond without displacing the Hg2+ ion from the dithiacrown ether cavity.

show abstract

“…5). Imermolecular interaction betweeq initial monomers is the most important factor in [2+2]-photocycloaddition.…”

mentioning

confidence: 99%

Crown ether styryl dyes

et al. 1998

View full text Add to dashboard Cite

Fax: + 7 (095) 135 5328Regio-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 prereaction 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 experinaental 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+21-photocycloaddition.

show abstract

Molecular simulation of the complexation effects on conformations and electronic absorption spectra of crown ether styryl dyes

Cited by 30 publications

References 5 publications

Supramolecular organic photochemistry of crown-ether-containing styryl dyes

Supramolecular organic photochemistry of crown-ether-containing styryl dyes

Synthesis, Structure, and Ion Selective Complexation of Trans and Cis Isomers of Photochromic Dithia-18-crown-6 Ethers

Crown ether styryl dyes

Contact Info

Product

Resources

About