Substitution effect, absorption, and fluorescence behaviors of some benzoaza-15-crown-5 derivatives upon cation complexation in solvent extraction were studied. The introduction of a substituent on the nitrogen atom in benzoaza-15-crown-5 enhanced extractabilities in the solvent extraction of aqueous alkali metal picrates. The nondonating substituents raised the cation selectivity for Na(+) over K(+), but the donating substituents reduced the cation selectivity. The absorption and fluorescence spectral behavior was different with the alkali metal cations.

The photoinduced electron transfer of tri-1-naphthyl phosphate and related compounds sensitized by 9,10-dicyanoanthracene (DCA) in acetonitrile produces 1,1'-binaphthyl and the corresponding biaryl. The quenching rate constant of the DCA fluorescence is calculated to be equal to the diffusion-controlled rate constant from the Stern-Volmer analysis and the fluorescence lifetime measurement. The free energy change calculated from the redox potentials and excitation energy of the singlet excited DCA indicates that the quenching process occurs exergonically to give the tri-1-naphthyl phosphate radical cation and DCA radical anion through electron transfer from tri-1-naphthyl phosphate to the singlet excited DCA at the diffusion-controlled rate. On the basis of spectroscopic and kinetic studies with laser flash photolysis, pulse radiolysis, and gamma-radiolysis, the radical cation of tri-1-naphthyl phosphate forms an intramolecular pi-dimer radical cation with face-to-face interaction between the two naphthyl groups within 8 ns of the electron pulse. The 1,1'-binaphthyl radical cation is eliminated at the rate constant of k(r) = 5.3 x 10(5) s(-)(1) from the intramolecular pi-dimer radical cation. Branching ratios of the reaction pathways are estimated for the reactive intermediates such as the tri-1-naphthyl phosphate radical cation and its intramolecular pi-dimer radical cation from the rate constants and quantum yields. The electron-withdrawing character of the P(O) group in the O-P(O)-O spacer is responsible for the elimination of the binaphthyl radical cation. The DCA-sensitized photoinduced electron-transfer reaction of the tri-1-naphthyl phosphate is compared with the direct photoreaction.

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The preparation of non-permselective membrane for the divalent cation was attempted by coating it with thin vinylon film on one side of a commercial cation-exchange membrane. When the coating surface of the cationexchange membrane was set on the concentration-compartment side (cathode side), the permselectivity coefficient of the calcium ion to the sodium ion was equal to that of untreated cation-exchange membrane and no effect of the selective treatment was recognized. However, when the coating sufrace was directed to the desalting-compartment side (anode side), an effect of the selective treatment was observed; in this case, the permeability of the calcium ion was more depressed, corresponding with the formalation degree of the selective-treatment membrane; for example, the permselectivity of the calcium ion for the membrane which was formalated for 180 min at 30°C decreased about one half compared with the untreated membrane. The electric resistance of the cation-exchange membrane increased upon the coating with the vinylon film, and especially the resistance of the calcium ionic-form membrane indicated a remarkable increase.