Substituent effects on the colour, dyeing and fastness properties of 4-N-β-cyanoethyl-N- β-hydroxyethylaminoazobenzenes part I—monosubstituted derivatives

Synthesis and characterization of hetarylazo disperse dyes derived from substituted N‐β‐acetoxyethylanilines—Application on cellulose acetate

“…Contrary to some studies on the dye structure–light fastness relationship10 indicating that the introduction of electron withdrawing substituents and increase in electron mobility in the molecule decrease light fastness of nonprotein substrates, the results in Table II indicate that this is not occuring: Dyes 2(a,b) with the strong electron acceptor nitro group in the benzothiazolylazo moiety and the benzisothiazolylazo dyes 3(a,b) exhibit singificantly higher light fastness ratings than dye 1a with the electron donor methoxy group in the benzothiazolylazo component. Furthermore, the presence of the acetylamino group and the replacement of the N ‐ethyl group with N ‐acetoxyethyl in the coupling component of dyes 2b and 3b and the subsequent increased electron mobility in the molecule compared to 2a and 3a does not result in a decrease of light fastness, but rather in a slight increase (light fastness of 2b and 3b in 1% o.w.f.…”

Effects of Light on Materials in Collections: Data on Photoflash and Related Sources

“…The ongoing research by this group should continue to provide useful data in the future. Mehta andPeters (1981, 1982) investigated the lightfastness of cellulose acetate and polyester fibers dyed with many different derivatives of substituted aminoazobenzene dyes. All of these compounds had absorption maxima in the blue in ethanol solution; that is, they are yellow dyes.…”

Dyeing with Disperse Dyes

“…However, anomalously low fastness arises with o-nitro substitution. The deleterious effect has been ascribed to the proximity of the negative charge on the nearest oxygen of the nitro function to the azo group preventing electron delocalization, ultimately lowering the bond order of the -nitrogen-carbon link and therefore increasing susceptibility to photolytic cleavage (Mehta & Peters, 1981). In the 4-aminoazobenzene series, variation of the terminal amino groups provides an important means of increasing light fastness on polyester.…”