No abstract

The absorption spectra of 9-anthroic acid (9-anthracenecarboxylic acid) in ethanol have been measured as a function of solute concentration. It was revealed that 9-anthroic acid forms a hydrogen-bonded dimer. The equilibrium constant for dimer formation was determined to be 6.6×104 mol−1 1 in ethanol at 298 K. The fluorescence spectra of 9-anthroic acid have been investigated as a function of concentration and temperature in various solvents. An excimer mechanism was proposed for a broad fluorescence of 9-anthroic acid; the hydrogen-bonded dimer is excited and then associates with an unexcited hydrogen-bonded dimer to form an excited tetramer from which the broad fluorescence occurs.

COONTER-J / (imm) / ~.~ CdSe SnO z ~lM.m ~O.I~m

No abstract

Electrochemical properties of WO3 films prepared by vacuum evaporation and stored in high humidity atmosphere have been studied in organic electrolytes. Structures of the film have been analyzed by electron diffraction analysis and x‐rays. It has been found that the evaporated amorphous WO3 film is crystallized to form WO3·H2O crystal and furthermore H2WO4·H2O from surface layer to bulk layer in high humidity air. Hydrated WO3·xfalse(H2Ofalse) crystal layer may act as a high resistant layer on the electrochemical reaction, so that the hydrated layer, remarkably, loses the electrochromic activity.