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The protonation mechanism of the aromatic hydrocarbon radical anions, such as biphenyl, naphthalene, phenanthrene, anthracene, 1,2-benzanthracene, and pyrene, in dimethylformamide (DMF) and water mixtures was studied. Three methods of measuring the concentration of the radical anions, i.e. polarography and ESR and UV absorption spectroscopy, were compared with each other by making simultaneous measurements of the same anthraquinone radical anion solution. A good linear relation of the polarographic anodic diffusion current to the UV absorbance was found, while the ESR signal intensity had linear relations with neither of the others in the system which contained an excessive number of parent molecules, 2×10−3M. The change in the visible absorption spectra of the aromatic hydrocarbon radical anions as a function of the time suggested that all the aromatic hydrocarbon radical anions decay by a first-order reaction. As a result, the radical anions were considered to decay through the following sequence:R\ewdo...

The rates of the protonation of aromatic hydrocarbon radical anions with water in dimethylformamide (DMF)-water mixtures were measured by means of the decay of the visible absorption maxima of radical anions with time. The rates were found to be greatly accelerated by the increasing water content in DMF-water mixtures. This behavior suggests that the negative charge is much more localized in the transition state than in the original radical anion. The rate constants in DMF could be obtained by extrapolation. The correlation of these rate constants to the molecular structure of radical anions was discussed on the basis of the results of HMO calculations. This correlation and the solvent effect could be interpreted by means of the charge-transfer mechanism.

From the viewpoint of the interaction between the oxidized or the reduced form of a depolarizer and solvents, the solvent effect on the half-wave potentials was studied. Another factor affecting the E1⁄2, i.e., pH or ion-pair formation, was also examined. The correction for the liquid junction potential was carried out by the use of the ferrocene standard. The reduction products, radical anions or dianions, were found to be stabilized by the hydrogen-bonding with water where the hydrogen-bond interaction of the dianion was stronger than that of the monoanion. Aromatic hydrocarbon radical anions, whose charges are dispersed over the molecule, were less susceptible to this solvent transfer than were the anthraquinone radical anion and the dianion, whose charges are strongly localized.

各種フッ素化界面活性剤水溶液の25℃ における表面張力の濃度変化を測定した。炭素数が8～9以上のフッ素化界面活性剤は一般にクラフト点が高く,室温ではミセルを形成せず水和固体がより低濃度で析出してくるため表面張力が十分に低下しないものがあるが,室温でミセルを形成するものは,表面張力が15～20dyne/cmまで低下する。n-C7F15COOMeとその異性体i-C7F15COOMeについて表面張力を測定し炭化フッ素鎖の末端の枝わかれの影響を調べた。ナトリウム塩については枝わかれ構造の方がCMC以下では1～2dyne/cmCMC以上では4.4dyne/cm低い表面張力を示した。酸については低濃度では枝わかれのある方がよく低下するが高濃度では直鎖の方が低くなった。適度の枝わかれをもった方がクラフト点は低下するので,枝わかれ構造の炭化フッ素鎖をもったものの方が使用に便利な場合が多いであろうどフツ素化界面活性剤とドデシル硫酸ナトリウムとの混合物の表面張力の濃度変化の測定によれば,25dyne/cm程度の表面張力の水溶液を得るにはフッ素化界面活性剤を炭化水素型界面活性剤で20～50%程度までうすめても可能であることが示された。通常の炭化水素型界面活性剤と混合すると,気一液界面の表面張力の最低値は少々高くなるものの,油0水溶液間の界面張力を低下させ得るのでγW/A+γO/W

The energy distribution curves of the photoelectrons emitted from naphthacene (C 18 H 12 ) crystal in the vacuum ultraviolet region were measured by an ac modulated retarding potential method. The peaks in the curves, 5.8 3 , 7.2 8 , 8.2 9 , 8.7 0 and 9.4 0 eV, are considered to be associated with the valence bands of the naphthacene crystal.

Photoemission measurements in the vacuum ultraviolet region from organic compounds, which contain benzene, naphthalene, anthracene and pyridine ring systems, were carried out. The change in the spectra upon condensation is discussed in terms of polarization energy.

Enthalpy and entropy of solution of non-polar solutes in water diverge strikingly from the normal behavior established for regular solutions. This abnormality has been considered mostly due to the iceberg formation around solute molecules in water. The abnormal solubility and enthalpy and entropy of solution of non-polar solutes in water have been explained coherently by the extension of the regular solution theory, taking into account the iceberg formation of water molecules. Unlike currently accepted views on the hydrophobic bonding, it is concluded that the enthalpy of mixing (interchange) of non-polar solute with water is large, but the enthalpy decrease due to the iceberg formation of water largely cancels the enthalpy increase of mixing (interchange). Thus, the apparent enthalpy of solution is small or negative at low temperature. It is concluded that 1) the small solubility of non-polar solutes in, water is not an entropy effect, and 2) the solubility of non-polar solutes is promoted by the iceberg...

Summary The rates of protonation of aromatic hydrocarbon radical anions with water in the DMF—water systems were measured by the stopped flow method. Apparent first-order rate constants of the order of 10 s−1 were obtained by this method. These rate constants were compared with those calculated from the polarographic limiting currents on the basis of two possible mechanisms, i.e. the e.c.e. mechanism: R + e ⇌ R ⨪ R ⨪ + H 2 O → R H ⋅ + O H − R H ⋅ + e ⇌ R H − and the regeneration mechanism: R + e ⇌ R ⨪ R ⨪ + H 2 O → k R H ⋅ + O H − R H ⋅ + R ⨪ → fast R H − + R Good agreement was found between the rate constants of protonation measured by the stopped flow method and those calculated on the basis of the regeneration mechanism. The regeneration mechanism was justified also by the observation that it leads to rate constants which are independent of drop-time.

The photoemission spectrum of polyethylene was measured in the vacuum ultraviolet region. The highest energy of the valence band, 8.5 eV, and the band gap energy, 8.0 eV, obtained are compared with the results of theoretical calculations by other authors.

Ag 2 F was made by the electrolysis of aqueous silver fluoride solutions. The work function of this metallic compound was estimated from the threshold value of photoelectric emission, 5.5 4 eV, and also from the photoelectron spectroscopical method, 5.4 9 eV.