Mono-Anchor Dyes

Most mono-anchor dyes are derivatives of cyanuric chloride (2,4,6-trichloro-1,3,5-triazine [108-77-0]), a molecule of wide synthetic potential because the three chlorine atoms on the triazine ring differ in their reactivities [12], The first chlorine atom exchanges with nucleophiles in water at 0 - 5 °C, the second at 35 -40 °C, and the third at 80 - 85 °C. A wide variety of triazinyl dyes can thus be prepared by careful selection of the reaction conditions. Condensation of cyanuric chloride with a chromophore ( Chrom. ) containing an amino group yields the highly reactive dichlorotriazinyl dyes 1 [11]. These very reactive dyes are sensitive to hydrolysis, and a suitable buffer is usually added to the powdered dye to increase its stability [13], 

When two of the chlorine atoms are substituted, for example with amino or alkoxyl groups, monochlorotriazinyl dyes 2 are obtained. These are considerably less reactive, and hence react with cellulose in the exhaust dyeing process only at relatively high temperature (80°C). Such dyes are especially advantageous for printing [14], 

The reactivity of monochlorotriazinyl dyes can be increased by replacing chlorine with fluorine (3), which allows the exhaust process to be carried out at 40°C [15], 

Reaction of monochlorotriazinyl dyes with tertiary amines also yields highly reactive dyes 4. One advantage conferred by the ammonium groups in these dyes is high water solubility [16]. 

In addition to the 1,3,5-triazines, other classes of heterocycles are important for the dyeing of cotton. Especially noteworthy are the halopyrimidine dyes 5 [17], 

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Nitrogen adsorption. MCM-41 source material as well as silylated or dye-anchored samples are exhibiting isotherms of the type IV according to IUPAC nomenclature (Figure 3). The isotherms are showing mono- and multilayer adsorptions on the pore walls (p/p0 < 0.2), a reversible step at p/po = 0.3 and p/po = 0.24, respectively, and multilayer adsorption on the outer surface of MCM-41 (p/po > 0.35). Because the isotherms are very flat in the last region... 

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