Deviations in the electronic absorption spectra of di- and tri-arylmethane dyes

The first-frequency absorption bands of electronically unsymmetrical derivatives of Michler's Hydrol Blue show bathochromic deviations, in contrast to the behaviour of these bands in the spectra of related cyanine dyes. The first bands of analogous derivatives of Malachite Green may show either bathochromic or hypsochromic deviations.