A general formula for the difference of solvent shifts of fluorescence and absorption spectra in the approximation of long range dipolar interaction was derived using Ooshika’s theory of light absorption in solution. Measurements of fluorescence and absorption spectra of some naphthalene derivatives in various organic solvents were undertaken, and the data were analysed by the theoretical formula. The formula reproduces the experimental data satisfactorily, and from this fact it was concluded that the most predominant factor which determines the difference of solvent shifts of fluorescence and absorption spectra of these molecules is the interaction energy between solute and solvent molecules due to orientation polarization. The incremental values of dipolemoments in the excited state were estimated, and those for α-, β-naphthols and β-naphthyl methyl ether were interpreted as due to the increase of electron migration from the substituent in the excited state.

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1. The fluorescence and absorption spectra of aqueous solutions of quinoline, acridine and 2,8-diaminoacridine were observed at various pH values, and it became clear that the stabilization energy by proton addition is larger in the excited state than in the ground state. 2. The effects of hydrogen bonding and proton addition upon the spectra were confirmed to be the same in tendency. 3. On the basis of the fluorescence intensities in various organic solvents, some discussions were made about the contribution of non-bonding electron to the inner quenching of fluorescence. 4. The vapor spectrum of quinoline was-taken and line spectra were observed, which are most certainly attributable to n→π* transition.

Weekly paclitaxel administration for ATC patients can be of clinical benefit in a neo-adjuvant setting.

The oxygen up-take of irradiated aqueous solutions of xanthene dyes has been investigated by means of Warburg’s apparatus, and evidence for a switch-over from a D–O to a D–D mechanism is obtained from the variation of dye-concentration. This view is supported by the photobleaching rate and the oxygen concentration effect at high eosine concentrations (∼10−4m). The quautum yields (γo2) of the consumption are estimated and it is found that γo2(D–D) is larger than γo2(D–O).

Intersystem crossing probability \varphiSTA for fluorescein, eosin, erythrosin, methylene blue and thionine in the aqueous solution of pH 7.2 (only for fluorescein 0.05n NaOH solution) has been determined by comparing the quantum yield of the nonsensitized (Φ) and the sensitized photo-reduction (ΦS) on the basis of the relations Φ=\varphiSTAβA ΦS=\varphiSTDβγA, where βA is the fraction of triplet dye molecules that undergo reduction, \varphiSTA and \varphiSTD are respectively for acceptor (dye) and donor (sensitizer), and γ is the energy transfer efficiency. This was assumed as unity. ATU and EDTA were used as a reducing agent. 1,5-Naphthalenedisulfonic acid and 1-anthracenesulfonic acid were used as sensitizers. The above relations and assumption have been found to hold satisfactorily. The \varphiSTD values for two sensitizers were determined using erythrosin as a reference substances for which \varphiSTA was assumed to be unity. \varphiSTD obtained was 0.88 for 1,5-naphthalenedisulfonic acid, and 0.82 for 1-anthracenesulfonic acid. \varphiSTA values for dyes obtained were: fluorescein (0.021) eosin (0.64) erythrosin (1.0) methylene blue (0.52) thionine (0.55). Using these \varphiSTA values, the rate constants for the following elementary reactions have been evaluated (A, dye: RH2 reducing agent): AT+RH2→reaction, AT+RH2→deactivation, AT+A→reaction or deactivation.

The intermediate species which are produced in the course of the photoreduction of methylene blue have been investigated by flash photolysis in plain aqueous, borate and phosphate buffer solutions with and without reducing agents. In an acidic solution, an absorption band with the lifetime of 30μsec. appears at 375 mμ, while in neutral and basic solutions, two bands appear, at 415 and 520 mμ, with lifetimes of 70∼90 μsec. The bands at 375 and 415 mμ are considered to be due, respectively, to the acidic and basic forms of the triplet state, since the transient spectra change with pH, making an isosbestic point. The band at 415 mμ is overlapped by another one with a lifetime longer by several hundred microseconds; this is presumed to be semiquinone. The intensity of the band at 520 mμ decreases upon the addition of reducing agents and increases upon the introduction of oxygen. Hence, this band may be due to the halfoxidized form of the dye. These results support the reaction scheme that the excited state of the dye reacts with the ground state, which has been proposed in the investigation of steady light photobleaching.