Electronic spectral study of interaction of electron donor – acceptor dyes in the ground and excited state with a metal ion. Effect of molecular structure of the dye

Effective Tuning of Ketocyanine Derivatives through Acceptor Substitution

“…The charge transfer band could be either due to the donor amine being strongly coupled to the acceptorm oiety or to the interaction between the amine and the iminium species through the backboneo f the dye in ac yanine-like structure. The latter is possible in the case of the stronger acceptors (DAA-Fl-PI,D AA-Fl-6O, DAA-Fl-6S), because localizing anegative charge on the acceptor moiety is believed to aromatize those units, [17,22,23] allowing for agreater stabilization of the charge-transfer interaction. [24,25] In order to gain further insight into the electronic structure of the ketocyanine dyes, 1 HNMR spectra were taken and compared.…”