ABSTRACT
Abstract .......................................................................................................258 15.1 Aim and Background .........................................................................258 15.2 Introduction .......................................................................................259 15.3 Experimental Part ..............................................................................260 15.4 Results and Discussion ......................................................................261 15.5 Conclusion .........................................................................................270 Acknowledgments .......................................................................................271 Keywords ....................................................................................................271 References ...................................................................................................271
The effect of interaction with anionic polymers (DNA, poly(sodium 4-styrenesulfonate)) was studied on cis-trans isomer equilibrium and spectral and fluorescent properties of a number of oxacarbocyanine dyes: 3,3′-diethyloxacarbocyanine iodide (K1), 3,3′-diethyl-9-methyloxacarbocyanine iodide (K2), 3,3′-dimethyl-9-ethyloxacarbocyanine iodide (K3), 3,3,’9-triethyl6,6′-dimethoxyoxacarbocyanine iodide (K4), and 3,3,’9-triethyl-5,5′- dimethyloxacarbocyanine iodide (K5). The interaction of the dyes with anionic polymers leads to the formation of stable noncovalent complexes. A shift of the cis-trans isomer equilibrium toward the formation of the trans-isomer was observed for meso-substituted oxacarbocyanine dyes in the presence of anionic polymers, which determined in many respects the spectral effects observed upon the complexation of the oxacarbocyanine dyes. A steep rise of fluorescence (due to binding of the trans-isomer) in a complex with DNA is favorable for using oxacarbocyanine dyes to determine DNA.
