Dye coupling

Azo-stilbene dyes formed by diazotization of a condensation product containing primary amino groups and coupling with azo dye coupling components, eg. Direct Brown 29 (Cl 40505) (6) ... 

The low cost of sulfur dyes, coupled with good fastness properties and the ease of appHcation, continues to ensure a high consumption. The number of manufacturers has fallen since the 1960s and production is mainly confined to the United States, U.K., Germany, and Spain. There is one principal producer in each of these countries. There are other, less well-known manufacturers in Russia, the People s RepubHc of China, South Korea, Japan, and Bra2il (Table 7). 

The complete reaction scheme is shown in Fig. 5.3-7, while Fig. 5.4-51 gives a simplified representation. 1-naphthol (A) is primarily coupled with diazotized sulphanilic acid (B) to form monoazo dyes coupled in para and ortho positions (p-R and o-R, respectively). This reaction is first order in both A and B. Each of the primary products can react with diazotized sulphanilic acid to form bisazo dye (5). Rate constants at 298 K and pH 10 are ku = 10600 m mof s k2i = 1 22 = 1.7 m mor s (see Fig. 5-4-51). 

Stewart, W.W. (1978) Functional connections between cells as revealed by dye-coupling with a highly fluorescent naphthahimide tracer. Cell 14, 741. 

Brosillon S, Djelal H, Merienne N, Amrane A (2008) Innovative integrated process for the treatment of azo dyes coupling of photocatalysis and biological treatment. Desalination 222 331-339... 

Hatton, G. I. and Yang, Q. Z. Synaptically released histamine increases dye coupling among vasopressinergic neurons of the supraoptic nucleus mediation by H[ receptors and cyclic nucleotides. /. Neurosci. 16 123-129,1996. 

Van der Schoot C, van Bel AJC. Mapping membrane potential differences and dye coupling in intemodal tissues of tomato. Planta 1990 182 9-21. 

The advantage of fluorescent dyes coupled to primary antibodies is the fast result obtained with the direct method. Another advantage is the possibility to label more than one antigen at the same time. In plant material, it is important to take into account the possible autofluorescence of the tissue. Disadvantages can be the lack of orientation in the tissue and photobleaching of the dyes. The latter problem can often be... 

The l-arylpyrazol-5-ones (4.9), prepared by the two-step condensation of an arylhydrazine with ethyl acetoacetate, are the most commonly used coupling components for the synthesis of greenish yellow azo dyes. Coupling occurs at the 4-position of the pyrazolone ring which, as in the case of the acetoacetarylamides discussed above, is activated towards electrophilic attack by the two flanking unsaturated carbon atoms (Scheme 4.14). 

Chromogenic development is the dye-coupling process in colour photography. 

No effect permeability = as assessed by dye coupling gj = assessed by measurement of electrical ... 

Another group of transmitters involved in the control of the cardiovascular system by the autonomous nervous system includes the catecholamines, adrenaline and noradrenaline. In acinar submandibular gland cells of the rat the administration of 10 4 mol/1 adrenaline elicits a reduction in dye coupling from 97 to 75.3% dye-coupled cells [Kanno et al., 1993]. This could not be mimicked with isoprenaline, but was inhibited with phenoxybenzamine. Thus, the uncoupling effect of adrenaline in this preparation is mediated by stimulation of the a-adre-noceptor, whereas a stimulation of the P-adrenoceptor has no effect. 

Other investigators observed an increase in gj in response to TPA [Kwak and Jongsma, 1996 Spray and Burt, 1990]. Kwak and Jongsma [1996] found an increase by 16 + 2% in gj in neonatal rat cardiomyocytes after application of 100 nmol/1 TPA (intracellular calcium was buffered with 10 mmol/1 EGTA in the pipette solution). TPA shifted the frequency distribution of unitary conductances yj to lower sizes. However, TPA decreased dye coupling in these and other experiments [Kwak et al., 1995a],... 

In other cells, i.e. in rat submandibular gland, adrenaline (100 pmol/l) has been shown to decrease the percentage of dye-coupled cells [Kanno et al., 1993], whereas isoproterenol was ineffective, so that the authors concluded that the mechanism was transmitted via action on the -adrenoceptors. This was supported since the adrenaline effect could be suppressed by coadministration of 10 pmol/1 phenoxybenzamine. 

Beny JL, Connat JL An electron-microscopic study of smooth muscle cell dye coupling in the pig coronary arteries. Circ Res 1992 70 49-55. 

Dye-coupling/consumption techniques enable quantitation of functional groups on resin. However, this area is at an early stage of refinement more quantitative analytical methods for quantifying a diverse set of organic functional groups are required. 

Anthrimides and Other Linked Anthraquinones. Among the anthrimides (dia-nthraquinonyl-amines), only the a,(3 derivatives have achieved limited importance as vat dyes. Coupling two anthraquinone molecules via functional derivatives of the 2-aldehyde (or 2-carboxy) group offers another type of building block for vat dyes. Such compounds, e.g., 1-aminoanthraquinones, are linked in the 2-position via an azine or oxadiazole group, and all have good fastness. 

Monomethinecaynine Dyes The oldest dye of the this series is cyanine, a blue dye after which the whole class of dyes was named. Cyanine (42) was synthesized by Williams in 1856 from crude tar quinoline by quatemization with pentyl iodide, followed by treatment with alkali. The unsymmetrical monomethine dye coupled in the 2- and 4-positions of quinoline is termed isocyanine. 

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