Cyanine characteristics

Taylor, A.C., J. Davenport, and J.A. Allen (1995). Anoxic survival, oxygen consumption, and hemo-cyanin characteristics in the protobranch bivalve, Nucula sulcata Brown. Comp. Biochem. Physiol. 112 333-338. 

By varying the molecular stmcture, it is possible to synthesize dye initiators with the requited characteristics. The synthesis of polymethine dyes with different chain length, end groups, and substituents, or with other variations of the chromophore, has been summarized (3,4,9,21,73,74) (see also Cyanine dyes). 

Several types of nitrogen substituents occur in known dye stmetures. The most useful are the acid-substituted alkyl N-substituents such as sulfopropyl, which provide desirable solubiUty and adsorption characteristics for practical cyanine and merocyanine sensitizers. Patents in this area are numerous. Other types of substituents include N-aryl groups, heterocycHc substituents, and complexes of dye bases with metal ions (iridium, platinum, zinc, copper, nickel). Heteroatom substituents directly bonded to nitrogen (N—O, N—NR2, N—OR) provide photochemically reactive dyes. 

To detect adulteration of wine. Bums et al. (2002) found that the ratios of acetylated to p-coumaroylated conjugates of nine characteristic anthocyanins served as useful parameters to determine grape cultivars for a type of wine. Our laboratory utilized mid-infrared spectroscopy combined with multivariate analysis to provide spectral signature profiles that allowed the chemically based classification of antho-cyanin-containing fruits juices and produced distinctive and reproducible chemical fingerprints, making it possible to discriminate different juices. " This new application of ATR-FTIR to detect adulteration in anthocyanin-containing juices and foods may be an effective and efficient method for manufacturers to assure product quality and authenticity. 

Let us first recall some basic characteristics of the cyanine isomerization mechanism, as emerging from simple MO correlation diagrams like those of Fig. 1. In... 

There has been some interest in extending the absorption range of cyanine dyes to longer wavelengths into the near-infrared region of the spectrum. Consideration of the spectral data for thiazole derivatives 118-120 is of some interest in this respect. Cyanine dye 118 shows the characteristic visible absorption spectrum for a dye of this type, giving a... 

Lin T, Peng BX (1997) Synthesis and spectral characteristics of some highly soluble squarylium cyanine dyes. Dyes Pigm 35 331-338... 

Table 2 Effect of the addition of CB7 on the spectral characteristics and photostability of cyanine dyes in water [46, 48]...

The styryl series of laser dyes are structurally similar to the cyanines, except that one of the heterocyclic bases has been replaced by a styryl moiety. They are more efficient laser dyes than the corresponding cyanines because they exhibit larger Stokes shifts, but otherwise share most of the characteristics of the cyanines. There seems to be little development of styryl dyes in the infrared underway as biophysical probes. 

Spectra, but, in general, leaves the copper site the most exposed of the four cupredoxins. The sequence of Cbp is quite similar to that of stella-cyanin. Stellacyanin is a plant protein, also of unknown function, having visible spectra characteristic of type I copper, but lacking the methionine ligand found in all other type I proteins. A disulfide bond has been suggested as a potential copper ligand in stellacyanin the Cbp has both a methionine and the disulfide, so that prior to the structure determina-... 

Methods of analysis are needed to determine total phenolic content and the relative content of phenolic fractions by means of their different characteristics. Many analytical methods used for phenols have been empirical and not easily reproduced or rationalized (I). Procedures that are based on sound chemical principles and that are sufficiently verified deserve wider application. We are concerned here with recent work on such analyses for phenols in wines. Application cf these results may help solve a major problem in phenol research—the many different, too empirical, unrelatable values (ml KMn04, vanillin-to-leucoantho-cyanin ratio, etc.) obtained in different ways by different researchers. Uniform use of verified methods and uniform standards and methods of expressing results will aid in developing an understanding in this field. 

For this reason, the most studied application has been the use of optically active pH indicators as H+-selective ionophores to develop pH-selective optical sensors [38]. First, the optical and analytical characteristics in PVC membranes of a series of novel neutral pH indicators, a class of keto cyanine dyes [144], were studied in a conventional configuration. The absorption maxima of the dyes are located in the NIR region, which is very appropriate for applications using telecommunications components and the membranes show good performance during calibrations in the pH range 3-8.5. 

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