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Bichromophores

Quack M and Thdne H J 1987 Absolute and relative rate coefficients in the IR-laser chemistry of bichromophoric fluorobutanes tests for inter- and intra-molecular selectivity Chem. Rhys. Lett. 135 487-94... [Pg.2150]

A Ca2+-ion selective rigid -flexible - rigid type bichromophoric sensors based on the conformation liable bis-squaraine dyes 27 works on the principle of Cation-steered folding, which leads to dramatic perturbations in the optical properties as a result of exciton interactions [87],... [Pg.82]

DHT may occur over different tryptophan forms in proteins as they quite often have inhomogeneously broadened electronic spectra [31]. A very interesting case of DHT is described between two indole rings in bichromophoric solutes tryptophan dipeptide [32]. Such directed transport allows to correctly interpret spectral properties of dipeptide and other multichromophoric solutes. The theory of inductive-RET in solutions with inhomogeneous spectral broadening is given in Ref. [33]. In more detail, DHT mechanism will be explained in Sect. 2.2 (vide infra). [Pg.199]

Thomas, L, Netzel, K. N. and Zhao, M. (1995). Base-content dependence of emission enhancements, quantum yields, and lifetimes for cyanine dyes bound to double-strand DNA Photophysical properties of monomeric and bichromophoric DNA stains. J. Phys. Chem. 99,17936-17947. [Pg.289]

The synthetic applications 440) and mechanistic aspects 4411 of intermolecular photocycloaddition reactions of arenes to olefins have been reviewed recently. Intramolecular cycloadditions442a,b) have been studied in the context of the photochemical behaviour of bichromophoric molecules, as to investigate interchromophoric interactions in polyfunctional molecules. Three types of addition products can be formed in the photocycloaddition of benzene to an alkene (4.37)441. ... [Pg.54]

J. Kroon, A. M. Oliver, M. N. Paddon-Row, J. W. Verhoeven, Observation of a Remarkable Dependence of the Rate of Singlet-Singlet Energy Transfer on the Configuration of the Hydrocarbon Bridge in Bichromophoric Systems , J. Am Chem Soc 1990,112, 4868-4873. [Pg.292]

The J-aggregates of bichromophoric dye BCD (Fig. 7) formed on DNA were studied in [37]. While this dye was shown to be able to form J-aggregates with a rather broad absorption spectrum in water solution in the presence of NaCl, an addition of DNA also caused fluorescent J-aggregate formation with the appearance of narrow absorption band. Besides the fact of formation in the presence of DNA,... [Pg.149]

Schaberle FA, Kuz min VA, Borissevitch IE (2003) Spectroscopic studies of the interaction of bichromophoric cyanine dyes with DNA. Effect of ionic strength. Biochim Biophys Acta 1621 183-191... [Pg.157]

Some bichromophoric systems, whose structure is based on the donor-bridge-acceptor principle, can undergo complete charge transfer, i.e. electron transfer. The resulting huge dipole moment in the excited state explains the very high sensitivity to solvent polarity of such molecules. An example is FP (l-phenyl-4-[(4-cyano-l- ... [Pg.217]

De Schryver F., Collart P., Vandendriessche J., Goedeweeck R., Swinnen A. and Van der Auweraer M. (1987) Intramolecular Excimer Formation in Bichromophoric Molecules Linked by a Short Flexible Chain, Acc. Chem. Res. 20, 159-166. [Pg.246]

Mechanisms of Intramolecular Electronic Energy Transfer in Bichromophoric Molecular Systems Solution and Supersonic Jet Studies, Chem. Rev. 96, 1953—1976. [Pg.272]

Valeur B. (1989) Intramolecular Excitation Energy Transfer in Bichromophoric Molecules, in Jameson D. and Reinhart G. D. (Eds), Fluorescent Biomolecules,... [Pg.272]

Intramolecular redox reactions for bichromophoric compounds containing nitro and amino (or amino acid) groups have also been examined. For example4, irreversible... [Pg.749]

Interest in intramolecular energy transfer has also been reported and bichromophoric norbornadiene derivatives have been synthesized for this study111. Cao and coworkers112... [Pg.290]

B. Valeur, J. Pouget, J. Bourson, M. Kaschke, and N. P. Ernsting, Tuning of photoinduced energy transfer in a bichromophoric coumarin supermolecule by cation binding, J. Phys. Chem. 96, 6545-6549 (1992). [Pg.48]

B. Valeur, J. Pouget, and J. Bourson, Photoinduced electronic energy transfer in a supramolecular complex between a coumarin bichromophoric molecule and lead(II), 7. Lumin. 52, 345-347 (1992). [Pg.48]

In special cases of nonracemic compounds, both relative and absolute configuration can be determined by means of circular dichroism. Thus, the relative and absolute configurations of acyclic 1.2-, 1,2,3-, 1,2,3,4-, and 1,2,3,4,5-polyols can be determined by the bichromophoric exciton chirality method after a two-step derivatization [primary and secondary hydroxy groups are selectively esterified with 9-anthroyl chloride (2) and ( )-3-(4-methoxyphenyl)-2-propenoyl chloride (4), respectively] and comparison of the CD curves with references curves265. [Pg.468]

For example, compounds 5 obtained from 1,2,3-triols of type 1 provide CD spectra which distinguish characteristically and predictably between stereoisomers (bichromophoric exciton chirality method). Thus, relative and absolute configuration of such 1,2,3-triols can be deduced from a single measurement180. [Pg.468]

Other examples of determination of the absolute configuration of bichromophoric molecules having two or more rotamers in the equilibrium include naphthalene/A -vinyl carbamate in a 1,2,3,4-tetrahydropyridine derivative123, naphthalenc/purine in deoxyadenosine adducts124-126, phenanthrene/purine in deoxyadenosine and deoxyguanosine adducts127 and pyrene/purine in adenosine adducts128. [Pg.519]

The most frequently used acyl derivatives, i.e., benzoates and cinnamates substituted in the 4-position, are listed in Table 7. The analysis of the stereochemistry of the bichromophoric system including a benzoate (cinnamate) chromophore is greatly simplified by its preference for s-trans conformation at the C(0)-0 bond, in which the carbonyl group is staggered ca. 30° to either side of the carbinyl C H bond. Consequently the direction of the electric dipole moment of the charge-transfer transition is approximately parallel to the C(H)-Q bond (Figure 16). [Pg.519]

The pairwise additivity principle when applied to bichromophoric exciton-coupled systems, such as those composed of 4-bromobenzoate (BB) and 4-methoxycinnamate (MC) derivatives of cyclic polyols, yields more information from the CD spectra of complex molecules173. In such systems both degenerate ( homo") interactions, i.e., BB/BB and MC/MC, and nondegenerate ("hetero") interactions, i.e., BB/MC, contribute to the exciton CD spectra. As the homo exciton Cotton effects arc well separated (BB 236/253 nm, MC 287/322 nm) a unique pattern of CD curves is obtained for each derivative of cyclic tri- or tetraol. This method is particularly useful in identification of glycopyranosides174, a procedure essential for microscale structure determination of oligosaccharides by the exciton chirality method175. [Pg.525]

Perylene-linked systems represent another class of useful compounds for PET studies. Classic cases are 21 and 22. They represent a family of closely related bichromophoric systems with properties designed to utilize PET strategies . [Pg.201]

Bichromophoric Model Compounds Containing Phenyl or Naphthyl... [Pg.31]

Bichromophoric Compounds with Single Flexible Three... [Pg.32]

Electronic Energy Migration and Bichromophoric Processes in Aryl Vinyl... [Pg.32]

Bichromophoric model compounds can provide such standards, since these compounds can be highly purified and characterized by techniques inapplicable to polymers. For example, the racemic compound 2,4-diphenylpentane models the syndiotac-tic dyad of PS, while the meso 2,4-diphenylpentane models the isotactic dyad of PS. The 2,4-diarylpentanes are the best models of aryl vinyl polymers, since the populations of the rotational conformers of the model compounds are similar to those of the dyads of the polymer. [Pg.36]

The first question cannot be answered directly even for a bichromophoric compound capable of forming intramolecular excimers. The simplest kinetic scheme in fluid solution involves the six rates kFM, kM, kFD, kD, khM, and k(,D. The latter two... [Pg.40]

Phane compounds, i.e. two chromophores held face-to-face by at least two hydrocarbon links (4) Sandwich dimers, which are chromophore pairs produced by photolysis of photodimers in rigid matrices and (5) Bichromophoric compounds having a single saturated hydrocarbon linkage, which form intramolecular excimers as allowed by the rotational isomers of the linkage. In each case, we will utilize the intermolecular excimer formed in solution as the standard against which the properties of constrained excimers will be measured. [Pg.47]

Bichromophoric Compounds With Single Flexible Three Atom Linkages 2.43.5.1 Survey of Interunit Linkages... [Pg.54]

Comparison of Polymer and Bichromophoric Model Compound Fluorescence in Dilute Solution... [Pg.68]

For excimer-forming bichromophoric compounds in solution, the probability M of ultimate monomer decay in Eq. (1) is given by 37)... [Pg.68]

The excimer formation and dissociation rates in the above are primed, to show that they are due to backbone rotations and to distinguish them from the rigid-matrix processes described in Table 4. Each chromophore has only one neighbor, and the values of M for the two chromophores are identical. Energy migration cannot increase the fluorescence ratio of bichromophoric compounds, since there is only one dyad. [Pg.68]


See other pages where Bichromophores is mentioned: [Pg.267]    [Pg.751]    [Pg.291]    [Pg.352]    [Pg.1242]    [Pg.513]    [Pg.517]    [Pg.526]    [Pg.529]    [Pg.31]    [Pg.32]    [Pg.33]    [Pg.40]    [Pg.41]    [Pg.66]    [Pg.74]   
See also in sourсe #XX -- [ Pg.53 , Pg.54 ]

See also in sourсe #XX -- [ Pg.220 , Pg.220 ]

See also in sourсe #XX -- [ Pg.380 , Pg.413 , Pg.418 ]




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Bichromophore molecules

Bichromophores Increasing Excited-State Lifetimes

Bichromophoric dyads

Bichromophoric molecules

Bichromophoric photochromes

Bichromophoric structure

Bichromophoric system

Intramolecular, bichromophoric

Wave Functions and Matrix Elements of Bichromophores

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