Cyanine sensitizer, monolayer

Figure 2. Arrangement of layers in monolayer assembly of cyanine sensitizer (C) and viologen electron acceptor (A) on glass coated with an arachidic acid spacer...

The number of dye molecules adsorbed by a silver halide grain in conventional sensitized emulsions is large. If the area occupied by an adsorbed molecule is 60 A2, an area close to that estimated for several cyanine and carbocyanine dyes, the number of molecules per square micron at monolayer coverage would be... 

In a layer system with a monolayer of tifN -dioctadecylthiacyanine the cyanine is excited at 405 nm and transfers energy to the merocyanine which emits a sensitized fluorescence. The fraction of merocyaninc is periodically varied by short pulses of UV radiation at 366 nm (increase of fluorescence at 675 nm) and green light, and 545 nm (decrease of fluorescence at 675 nm), respectively. 

This work explored whether supersensitization of electron transfer could be demonstrated in a monolayer assembly. We also studied the properties of excited cyanine dyes, the class of compound used almost exclusively as photographic spectral sensitizers (26). Kuhn, Mtfbius, and co-workers have demonstrated the detailed information that can be gained on energy and charge-transfer properties through the use of monolayer assemblies of such dyes (23, 27). We emphasized investigations of cyanine dye... 

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