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The fluorescence behavior from SAM of dendron with rhodamine B as a center Yukito Naitoh, Akira Otomo, Hideki Miki, Isao Aoki, Shiyosi Yokoyama We studied energy transfer between rhodamine B molecules centered in each corn-shaped dendrons that forms self-assembled monolayer (SAM) film on an Au substrate. A SAM film using dendron moiety as a spacer can change the distance between rhodamines depending on the size, so that the energy transfer from an initially photo-excited rhodamine to its surrounding molecules can be controlled. The absorption spectrum of a SAM film for each generation of dendron was measured to ascertain a linear correlation between the generation and the distance. Picosecond time-resolved fluorescence spectra showed clear differences in the fluorescence decay dynamics between third-generation (G3) and fourth-generation (G4) dendron SAM films. In addition, we found that gdryh or gweth dendron SAM considerably influenced fluorescence behavior. As a result, the use of gweth G4 SAM is suitable in preserving photo-excitation energy. This is because it gave almost equal dynamics to G4 dendron in the dilute solution and prevented deactivation by energy dissipation. doi:10.1016/j.tsf.2007.04.118 |