Anionic Azo Dyes

Anionic dyes include many compounds from the most varied classes of dyes, which exhibit characteristic differences in structure (e.g., azoic, anthraquinone, triphenylmethane, and nitro dyes) but possess as a common feature water-solubilizing, ionic substituents. The anionic azo dyes which are discussed here constitute the most widely used group of this class of dyes. 

From the chemical standpoint the group of anionic azo dyes includes a large proportion of the reactive dyes which, in addition to the usual structural characteristics, also contain groups that can react with functional groups of the fiber during the dyeing process (see Section 3.1). 

The anionic azo dyes also include formally the metal-complex dyes, which are derived from o,o -disubstituted azo dyes and which can be metallized not only on... 

The anionic azo dye Orange II complexation with a-, and / -CD follow one-step reaction mechanism [23], Data obtained by the stopped-flow method and UV as well as NMR are rationalized in terms of inclusion direction of the naphthalene side of the guest azo molecule along the short axis into the cavity of both a- and /LCD. 

Takayanagi, T., Tanaka, H., and Motomizu, S. Ion association reaction between divalent anionic azo dyes and hydrophobic quaternary ammonium ions in aqueous solution. Anal. Sci. 1997, 13, 11-18. 

In the early 1950s, Karush reported on the differential binding of the enantiomers of an anionic azo-dye, first to bovine (14) and then human (15) serum albumins. Although not of direct clinical significance, the work of Karush created an avirareness of the potential of enantioselectivity in binding to plasma proteins and marks the first reports of species differ-... 

The first useful application of the protein error of indicators arose from the early studies of Klotz (K22, K23). In the presence of low concentrations of bovine albumin, but not of 7-globulin or gelatin, the absorption spectra of a number of different dye solutions have been found to undergo pronounced shifts. Albumin-binding data and absorption maxima of many anionic azo dyes have been listed (M3). Three of these dyes have been utilized for protein estimation. 

Funar-Timofei, S. and Schmirmann, G. (2002) Comparative molecular field analysis (CoMFA) of anionic azo dye-fiber affinities. 1. Gas-phase molecular orbital descriptors./. Chem. Inf. Comput. Sci., 42, 788-795. 

Anionic Azo Dyes this group of azo dyes are characterised by the presence of one or more water-solubilising ionisable substituents, most often the readily available sulphonic acid group. Normally, the presence of such anionic group can increase the solubility of the dyes. 

Potassium River, tap water l lv/v benzene chlorobenzene UV-Vis 1 x 10-6 mol L-1 C-FIA membrane for phase separation K-crown ether associated with anionic azo dye [479]... 

S. Motomizu, M. Onoda, M. Oshima, T. Iwachido, Spectrophotometric determination of potassium in river water based on solvent extraction of the complex formed with a crown ether and an anionic azo dye using flow injection, Analyst 113 (1988) 743. 

Almost every leather is dyed, mostly with synthetic organic colors. The majority of the dyes used are anionic azo dyes which bind to the cationic surfaces of the leather. For completion of the dyeing process, formic, acetic or lactic acid is added. Afterwards, basic dyes can be applied which give the leather a brilliant... 

Chitosan/kaohn/nanosized Y-Fe Oj composites were prepared by a micro emulsion process and characterized by TEM, SEM, and WAXRD. Many pores and pleats were visible on the surface of the composites and provided a good condition for dye adsorption. Methyl orange was selected as a model anionic azo dye to examine the adsorption behavior of the composites. About 71% of methyl orange was adsorbed within 180 min, from 20 mg/1 at ph 6 by 1.0 g/1 adsorbent dosage. The composites can... 

Singh, V., Sharma, A. K., Tripathi, D. N., and Sanghi, R. (2009). Poly(methyl methacrylate) grafted chitosan An efficient adsorbent for anionic azo dyes. Journal of Hazardous Materials 161, 955-966. 

The sorption of anionic azo dyes involves mainly the hydrogen bonding, however, the formation of inclusion complexes with p CD molecules is also important. Moreover, hydrophobic interactions (pollutant-poUutant and pollutant-polymer), and add-base interactions between the sorbent and the pollutant, as well as physical adsorption due to the polymer network occur. The p CD polymers can be easily regenerated using ethanol their sorption capacity was not decreased by this procedure. 

Used as 0.0 IM aq. soln. of perchlorate salt for extraction-photometric detn. of Cu, Co, Ni (as ion-pairs with anionic azo dyes e 50000, CHCI3). Cryst. Sol. acid solns. 

Motomizu, S., M. Oshima, Y. Gao, Flow injection spectrophotometric determination of anionic surfactants with an anionic azo dye and a quaternary ammonium ion. Anal. ScL, 1991, 7(.Supp.), 301-304. 

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