Fluorescein, differences from rose

Singlet lifetimes, fluorescence quantum yields, and singlet oxygen quantum yields are compared for Rose Bengal, Erythrosin, Eosin, and fluorescein in a number of different solvents in Table 11. In virtually every case water differs from the other solvents studied. 

Rose Bengal differs in reactivity from fluorescein and Eosin because of the iodines at C-2, C-4, C-5, and C-7 which differentiate the reactivity of the phenoxide from the carboxylate and make substitution at C-2 possible in lieu of substitution at C-6. Essentially three different kinds of Rose Bengal derivatives have been synthesized. The most common include derivatives with gegen ions other than sodium at both C-2 and C-6. Many esters of C-2 have been synthesized and compounds with a number of different gegen ions at C-6 have been reported. The rarest derivatives of Rose Bengal are the C-6 ethers, of which only three have been reported. 

Fig. 6.5. Change in viscosity number of (—) cis-1,4-polybutadiene and (—) trans-1,4-polybutadiene in benzene solution during visible light irradiation in the presence of oxygen and different dyes used as sensitizers (V, O) fluorescein (FL), ( , ) rose bengal (RS) (A, , A, ) methylene blue (MBL) (x) viscosity of solution irradiated without dyes [1785]. (Reproduced with permission from [1785] published by John Wiley Sons, Inc., 1976.)...

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