8-hydroxy 1,3,6 trisulfonate pyrene

Pouxviel J.C., Dunn B., Zink J.I. Fluorescence study of aluminosilicate sols and gels doped with hydroxy trisulfonated pyrene. J. Phys. Chem. 1989 93 2134-2139 Preston D., Ponxviel J., Novinson T., Kaska W.C., Dunn B., Zink J.I. Photochromism of spiropyrans in aluminosilicate gels. J. Phys. Chem. 1990 94 4167-1172 Sakka, Sumio, Sol-Gel Science. Tokyo Aguneshofu-sha, 1988... 

Recently, Hynes and coworkers have proposed a new perspective (a three-step mechanism) on intermolecular photochemical proton transfer in solution [96-99]. They performed femtosecond fluorescence and absorption measurements on pyranine (PyOH 8-hydroxy-l,3,6-trisulfonate pyrene) in aqueous solution, and found that the early events of the photoinduced proton transfer from pyranine to water involve three... 

Using pyranine (8-hydroxy-1,3,6-pyrene trisulfonate) as intraliposome pH indicator, the liposomes were prepared as above (as in section Preparation of 100 nm SSL Loaded with DOX via Transmembrane AS Gradient ) with the exception that pyranine (0.5 mM) was included in the hydration solution. Removal of untrapped pyranine was achieved by gel filtration on a Sephadex G-50 column, preequilibrated with either NaCl, KCl, sucrose or AS solution (according to need). All these solutions also contained lOmM Hepes buffer at the desired pH (usually pH 7.5). 

Figure 12.2 Molecular structure of 1-hydroxypyrene (IHP), 8-hydroxypyrene-l,3,6-dimethylsulfamide (HPTA) and 8-hydroxy pyrene 1,3,6-trisulfonate (HPTS).

Figure 5. The dependence of the rate of proton dissociation from excited 8-hydroxy-pyrene- 1,3,6-trisulfonate on the mole fraction of ethanol in water, and the respective proton conductivity of the mixtures. The rate of proton dissociation was measured by time resolved ( ) or steady-state ( ) fluorescence. The proton conductivity of the solutions (A) is normalized for pure water conductivity. Data taken from Erdey-Grutz and Lengyel (1977).

Figure 12 (line A) depicts the emission spectrum of hydroxy pyrene trisulfonate dissolved in diluted buffer (pH 5.0). At this pH, the ground state is fully protonated (pK0 = 7.7), but not so the first excited singlet state (pK = 0.5). The excited molecules dissociate and 95% of the emission is at the wavelength of the excited anion (515 nm). The dissociation can be prevented if the compound is dissolved in acid solution, pH < pK., such as 2MHC1 (line B). Under such conditions, we observe the emission of the neutral form with maximum at 445 nm. Upon ligation to apomyoglobin, the fluorescence of hydroxypyrene trisulfonate consists of two... 

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