Classification of Organic Colorants

PPP Calculations for Electronic Spectra of Cyanine Dyes (Part 2).

“…[10] In case of the conventional PPP MO calculation using the N•M-y. [ 11] the absorption maxima for cyanine dye series 1-5 are estimated shorter wavelengths than the observed ones,as is shown in Table 1 and Figs.…”