Electronic structure and solvatochromism of merocyanines based on N,N-diethylthiobarbituric acid

Kulinich, A. V.; Derevyanko, N. A.; Ishchenko, A. A.

doi:10.1016/j.jphotochem.2006.12.014

Cited by 37 publications

(26 citation statements)

References 13 publications

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“…In turn, in the absence of strong solvation and conformational effects, the latter are responsible for the width and shape of the electronic bands. The more pronounced the alternation of the bond orders, the stronger the vibronic coupling [12][13][14].…”

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Electronic structure and spectral fluorescence properties of umbelliferone and herniarin

et al. 2007

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We have studied the characteristic features of the spectral fluorescence properties of natural compounds (umbelliferone and herniarin) in aprotic and proton-donor solvents of different polarities. Based on quantum chemical analysis by the AM1 semiempirical method of the changes in the electronic charge and bond orders in the ground state and the first excited state, we have interpreted the anomalously high Stokes shifts and mirror symmetry of the absorption and fluorescence bands of these compounds in aprotic solvents. We have established that the fluorescence spectra of umbelliferone in water, ethanol, alkaline and acidic solutions differ considerably from the analogous spectra of herniarin. This is connected with detachment and transfer of a proton in the neutral form of umbelliferone upon photoexcitation, with possible formation (depending on the pH of the medium) of an anion, cation, or tautomer. Good agreement was achieved between the calculated and experimental values of the maxima for the electronic bands of these forms.

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Electronic structure and spectral fluorescence properties of umbelliferone and herniarin

et al. 2007

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“…For comparison, it should be noted that anionic dyes with the same length of the polymethine chain, based on the widely prolife rated withdrawing hetero fragment of diethylthiobarbi turic acid (which considerably deepens the color), absorb light in more short wave region (by 130 nm) than dye 5. 5 The bands of cationic pentamethine dyes, deri vatives of classic heterocycles indolenine, benzothi azole, and benzoxazole, 6 are also hypsochromically shift ed with respect to the absorption band of compound 5 bỹ 120-150 nm.…”

Section: Scheme 1 R = Ch 2 (Cf 2 ) 3 Cf 2 Hmentioning

confidence: 99%

“…6. Electronic absorption spectra of dyes 12 (1-3) and 12a (4)(5)(6) in dichloromethane (1,4), toluene (2,5), and water (3,6). In fact, in alcohols, in which these both factors are pro nounced much weaker than in water, the shape of the curve for dyes 12-15 comes nearer to that in polar aprotic solvents (see Fig.…”

Section: Scheme 1 R = Ch 2 (Cf 2 ) 3 Cf 2 Hmentioning

confidence: 99%

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Deeply colored anionic polymethine dyes derived from bis(2,2,3,3,4,4,5,5-octafluoropentyl) 9 H-fluorene-2,7-disulfonate

et al. 2009

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Deeply colored anionic polymethine dyes derived from bis(2,2,3,3,4,4,5,5 octafluoropentyl) 9H fluorene 2,7 disulfonate Anionic symmetric polymethine dyes have been synthesized based on bis(2,2,3,3,4,4,5,5 octafluoropentyl) 9H fluorene 2,7 disulfonate, which exhibit intensive absorption in the near IR region of the spectrum: pentamethine with an open polymethine chain (λ max = 790 nm) and nonamethine with six and five membered saturated rings at δ,δ´ positions of the chain (λ max = 1044 and 1086 nm, respectively). To make comparisons, anionic dyes with analogous structure of the polymethine chain, viz., 1,3 dimethylbarbituric and 1,3 diethylthiobarbituric acid derivatives, have been also synthesized. Quantum chemical analysis of the electron struc ture of the dyes has been performed. Their solvatochromism in polar solvents depends weakly on electrophilicity and nucleophilicity of the medium and is primarily determined by universal interactions. This is the reason that they, in contrast to cationic dyes, retain a high selectivity of absorption (sharp absorption bands) and universal contour of electronic bands in strong polar solvents even with the long polymethine chain. Special solvatochromic effects of the anionic dyes in weakly polar media have been revealed and interpreted. The role of a counterion in these effects has been analyzed.

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Merocyanines based on 1,3‐indanedione: electronic structure and solvatochromism

Kulinich

Derevyanko

Mikitenko

et al. 2010

J of Physical Organic Chem

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A series of merocyanines derived from 1,3‐indanedione and heterocycles of various electron‐donating properties was studied in detail. Their solvatochromic properties were explored in a wide range of solvent polarities to reveal the dependences of their chromacity and electronic structure on the key structural parameters – the properties of a donor heterocycle and the polymethine chain length. Also the dyes were studied by NMR spectroscopy and by quantum chemical calculations, both with the semiempirical AM1 and the non‐empirical density functional theory/B3LYP method. The solvatochromic properties of the explored dyes are rather close to those of merocyanines derived from malononitrile as acceptor group. Appreciable distinctions were observed only in protic ethanol; obviously, they are connected with the formation of solvent–solute H‐bonds in the case of 1,3‐indanedione derivatives. The electron‐acceptor properties of 1,3‐indanedione were found to be somewhat stronger in comparison with those of malononitrile even in aprotic solvents, contrary to the known literature data. Analysis of the merocyanines' molecular orbitals and simulation of their electronic spectra were carried out both in vacuum and in the solvent matrix, and the absorption electronic transitions were analyzed. Static nonlinear optical properties were calculated for both the new merocyanines and the corresponding cationic and anionic cyanine dyes. Copyright © 2010 John Wiley & Sons, Ltd.

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Electronic structure and solvatochromism of merocyanines based on N,N-diethylthiobarbituric acid

Cited by 37 publications

References 13 publications

Electronic structure and spectral fluorescence properties of umbelliferone and herniarin

Electronic structure and spectral fluorescence properties of umbelliferone and herniarin

Deeply colored anionic polymethine dyes derived from bis(2,2,3,3,4,4,5,5-octafluoropentyl) 9 H-fluorene-2,7-disulfonate

Merocyanines based on 1,3‐indanedione: electronic structure and solvatochromism

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