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.