Browsing by Subject "Chromatophore"

Now showing 1 - 3 of 3

Open Access
Convergent synthesis and light harvesting properties of dendritic boradiazaindacene (BODIPY) appended perylenediimide dyes
(2010) Bozdemir, O. A.; Yilmaz, M. D.; Buyukcakir, O.; Siemiarczuk, A.; Tutas, M.; Akkaya, E. U.
A convergent synthesis methodology, together with "click- chemistry" between azides and terminal alkynes, allows straighforward access to dendritic light harvesting systems. The novel dendrimer reported in this study has eight boradiazaindacene (BODIPY) units at the periphery and a perylenediimide (PDI) dye at the core. We have demonstrated that visible light is effectively collected as a result of the large absorption cross section of the dendrimer and efficiently channeled to the core PDI unit, resulting in a significant antenna effect. While being one of the very few energy transfer systems with a BODIPY and PDI chromophore pair, this novel dendritic molecule is one of the most efficient in light harvesting. The factors that may play important roles as the generation number increases also become apparent when emission characteristics were analyzed in comparison with a lower generation dendrimer.
Open Access
Design strategies for ratiometric chemosensors: modulation of excitation energy transfer at the energy donor site
(2009) Guliyev, R.; Coskun, A.; Akkaya, E. U.
Excitation energy transfer, when coupled to an ion-modulated ICT chromophore, creates novel opportunities in sensing. The direction of energy transfer and the point of ICT modulation can be varied as desired. In our previous work, we have shown that energy transfer efficiency between two energetically coupled fluorophores will be altered by the metal ion binding to the ICT chromophore carrying a ligand. There are two beneficial results: increased pseudo-Stokes shift and expanded dynamic range. Here, we explored the consequences of the modulation of energy transfer efficiency at the energy donor site, in a molecular design which has an ICT type metal ion-sensitive chromophore placed as the energy donor in the dyad. Clear advantages emerge compared to the acceptor site modulation: unaltered emission wavelength in the red end of the visible spectrum, while keeping a large Stokes shift and the ratiometric character. © 2009 American Chemical Society.
Open Access
Non-covalent functionalized SWNTs as delivery agents for novel Bodipy-based potential PDT sensitizers
(2009) Erbas, S.; Gorgulu, A.; Kocakusakogullari, M.; Akkaya, E. U.
Pyrenyl-functionalized distyryl-Bodipy sensitizer attached non-covalently to SWNTs was shown to generate singlet oxygen when excited at 660 nm with a red LED array; this work emphasizes the potential of SWNT as a viable alternative carrier of bioactive agents, including photodynamic therapy sensitizers. © 2009 The Royal Society of Chemistry.