Abstract: A radiation-sensitive element is disclosed including a radiation-sensitive layer comprised of a cobalt(III)complex and a photoreductant. A process is disclosed in which the photoreductant is converted to a reducing agent by exposure to electromagnetic radiation longer than 300 nanometers. The reducing agent is then reacted with a cobalt(III)complex. Images can be recorded directly within the radiation-sensitive layer or in a separate image-recording element or layer by use of the residual cobalt(III)complex not exposed or one or more of the reaction products produced by exposure. By using the ammonia liberated from ammine ligand containing cobalt(III)complexes on exposure in combination with imagewise and uniform exposures, positive or negative images can be formed in diazo image-recording layers or elements associated with the radiation-sensitive layer. By the selection of amine-responsive reducing agent precursors, the amines released by the cobalt(III)complexes cause an amplified image.

Abstract: A dye-forming or imaging composition, element and method are disclosed, wherein a cobalt(III) complex containing releasable ligands is converted to cobalt(II) and the ligands by heating in the presence of a first destabilizer compound. The temperature at which the conversion reaction is initiated is unexpectedly lowered by the addition of a second, different destabilizer compound.

Abstract: Imaging means, such as a tetrazolium salt, capable of reduction to form a visible image is present in a radiation-sensitive layer in combination with a photoreductant incorporating one or more labile hydrogen atoms and capable of producing a reducing agent precursor in radiation-struck areas of the layer. An image is produced in the layer by processing the layer after imagewise exposure to actinic radiation.

Abstract: A radiation-sensitive element is disclosed including a radiation-sensitive layer comprised of a cobalt(III)complex and a photoreductant. A process is disclosed in which the photoreductant is converted to a reducing agent by exposure to electromagnetic radiation longer than 300 nanometers. The reducing agent is then reacted with a cobalt(III)complex. Images can be recorded directly within the radiation-sensitive layer or in a separate image-recording element or layer by use of the residual cobalt(III)complex not exposed or one or more of the reaction products produced by exposure. By using the ammonia liberated from ammine ligand containing cobalt(III)complexes on exposure in combination with imagewise and uniform exposures, positive or negative images can be formed in diazo image-recording layers or elements associated with the radiation-sensitive layer. By the selection of amine-responsive reducing agent precursors, the amines released by the cobalt(III) complexes cause an amplified image.

Abstract: A radiation-sensitive element is disclosed including a radiation-sensitive layer comprised of a cobalt(III)complex and a photoreductant. A process is disclosed in which the photoreductant is converted to a reducing agent by exposure to electromagnetic radiation longer than 300 nanometers. The reducing agent is then reacted with a cobalt(III)complex. Images can be recorded directly within the radiation-sensitive layer or in a separate image-recording element or layer by use of the residual cobalt(III)complex not exposed or one or more of the reaction products produced by exposure. By using the ammonia liberated from ammine ligand-containing cobalt(III)complexes on exposure in combination with imagewise and uniform exposures, positive or negative images can be formed in diazo image-recording layers or elements associated with the radiation-sensitive layer.