Untersuchungen zum UV/Vis‐Spektralverhalten von Azofarbstoffen. XVIII. Substituenteneinflüsse auf die Absorptionsmaxima der n → π^*– und π → π^*‐Banden von 4‐N,N‐Diethylaminoazobenzenen

Abstract

Studies on UV/Vis Absorption Spectra of Azo Dyes. XVIII. Substituent Effects on the Absorption Maxima of the n → π* and π → π* Bands of 4‐N,N‐Diethylaminoazobenzenes The spectra of 27 substituted 4‐N.N‐diethylaminoazobenzenes are determined. The band systems can be separated by deconvolution into two Gaussian curves. The results so obtained show that the effects of substituents on n → π* and π → π* transitions are similar and that electron withdrawing substituents in the phenylazo residue cause a bathochromic shift of both the n → π* and the π → π* bands.

Biosurfactants from Urban Wastes As Auxiliaries for Textile Dyeing

“…These products are claimed by the manufacturer to be prepared for printing and dyeing and therefore to be desized, scoured, and bleached to contain no sizing, dyes, and resins. The dyes in Table 1 were synthesized as described in previous works [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32] and purified by crystallization from ethanol. The products purity was checked by TLC analysis performed on Macherey-Nagel 1, which were consistent with the literature data.…”