Abstract: The sensitization and fog-inhibition of hydroxy-tetraazaindene (TAI) was obtained asTAI was introduced into the AgCl emulsion. The varied amounts of Na₂S₂O₃ in the emulsion have little effect on the sensitization of TAI. The degree of sensitization by TAI varies with the amounts of its addition. The mechanism of the sensitization of TAI was studied by the exposing and the developing experiment. The results indicated that the sensitization of TAIwas not arose from developing process but from the effect of TAI on the latent image formatiom.It was suggested that the addition of TAI probably suppressed recombination of Ag₂S⁺ with photoelectrons by the results of IR spectra, cyclic voltammetry, and dielectric loss experiments, which might lead to the increase of the sensitivity of the AgCI emulsion.

Key words: hydroxy-tetraazaidene, AgCl emulsion, sensitizing effect