With cyanine dyes

A reaction of mixed molybdenum polyoxometalates (POMs) with cyanine dye has been used for highly selective and sensitive spectrophotometric determination of phosphorus(V) and arsenic(V). Color of the solution is considerably changed by reaction of Keggin POMs with styrene cyanine dyes. Derivatives of l,3,3-threemethyl-3//-indol - astrazone violet (AV 3R), astrazone rose, astrazone yellow, astrazone red were investigated. 

The valence-bond (resonance) description of the triphenylmethine dye Malachite Green (125) is illustrated in Figure 6.5. Comparison with Figure 6.4 reveals their structural similarity compared with cyanine dyes. Formally, the dye contains a carbonium ion centre, as a result of a contribution from resonance form II. The molecule is stabilised by resonance that involves delocalisation of the positive charge on to the p-amino... 

Davila J, Harriman A, Gulliya KS (1991) Photochemistry of merocyanine 540 The mechanism of chemotherapeutic activity with cyanine dyes. Photochem Photobiol 53 1-11... 

M Era, C Adachi, T Tsutsui, and S Saito, Organic electroluminescent device with cyanine dye Langmuir-Blodgett film as an emitter, Thin Solid Films, 210/211 468-470, 1992. 

A series of silica nanoparticles doped with cyanine dye DY-635 (Dyomics) were also prepared, characterized, and investigated in flow cytometry and fluorescence imaging applications [77]. Also these dye-nanoparticles demonstrate high, stable, and tunable fluorescence intensity and are useful for multicolor detection. 

Other compounds reported were conjugates with vasoactive intestinal peptide (VIP) and derivatives thereof [65, 67]. Based on VIP as the lead structure, it was shown that peptide conjugates with cyanine dyes could be prepared on solid cellulose supports to generate peptide libraries for drug screening and optimization [67]. 

Similar to the approaches followed with cyanine dyes (Chapter 3.1.3), attempts to enhance the selectivity of photosensitizers by conjugating to target-specific vehicles have been described [98]. The approaches included conjugates with antibodies [99, 100], antibody fragments [58, 101], peptides [102], the serum proteins albumin and transferrin [103,104] and estradiol [105]. 

Unfortunately there are no experimental results which could be compared with these theoretical curves. All experiments reported in the literature are either made with cyanine dyes showing some excited state absorption or with phthalocyanine dyes which have an extremely high intersystem crossing rate so that triplet populations cannot be neglected. 

Fig. 24. Structural model of monomeric and polymeric multilayer assemblies doped with cyanine dyes. The black bars represent the polydiacetylene rc-bond system (from Ref.

Random coil polymer (green) with cyanine dye (open circles) beginning to assemble on scaffold. Light tnrned off ... 

In fused azole or azine rings, methyl groups at carbon atoms adjacent to a nitrogen atom often have sufficient acidity to effect condensation with cyanine-dye forming synthons, especially after undergoing a reactivity-enhancing quatemization. Thus, for instance, methosulfates... 

Linn, C. R Pitner, J. B. Mize, P. D. Preparation of oligonucleotide directly linked with cyanine dye, conjugate fluorescence, and labeled oligonucleotide use as analytical reagent Can. Pat Appl. CA 2152446, 1996 Chem. Abstr. 1996,124, 309549. 

Mitsui Chemicals and Ricoh employ such phthalocyanine compounds for their CD-R products. Compared with cyanine dyes (usually pentacyanine dyes), phthalocyanine compounds are excellent with respect to light fastness and performance for high rate recording, but are much more expensive. Evaluation results of commercially available CD-R are available to consumers from the Internet web sites. In order to increase the demand for phthalocyanine compounds in CD-R recording materials, cost reduction may be the most significant hurdle to overcome. 

The structure of porphyrins in SAMs has been widely studied because of the strong and characteristic UV/vis absorption features of porphyrin chromophores (see Sect. 5.1) [78,142,144]. Porphyrins may form two different types of aggregation a face-to-face porphyrin 7r-aggregation (sandwich-type H-aggregate) and a side-by-side porphyrin tt-aggregation (J-aggregate) (Fig. 16). The J-type aggregation is often foimd with cyanine dyes [145,146]. 

FIGURE 7.9 Representation of electronic couplings associated with cyanine dye aggregation on DNA. Face-to-face stacking within a dimer leads to primary splitting, observed as a blue-shift in the absorption spectrum. End-to-end interactions between dimers yield secondary splittings of the blue-shifted band. 

Borate salts are especially useAil in combination with cyanine dyes. Depending on the cyanine used, there are different absorption maxima in the visible region with usually high molar extinction coefficients (e 10 L moP cm ). Radical formation by borate is illustrated in reaction (42). 

Zakharova, G.V. and Chibisov, A.K., Effect of polyfmethacrylic acid) on photoinduced processes with cyanine dyes in aqueous solutions (Khim. Vys. Energ., 35,454,2001), High Energy Chem., 35,417, 2001. 

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