Abstract: A photographic element comprising a support having situated thereon a silver halide emulsion, the emulsion comprising an alkynylamine compound of the formula: wherein Z represents atoms necessary to complete a 5 to 10-membered heterocyclic ring system, R.sup.1 represents hydrogen or an alkyl of from 1 to 5 carbon atoms, and R.sup.2 represents hydrogen, or an alkyl, aryl, heteroaryl, carbocyclic or heterocyclic group; andat least one dihydroxy aryl compound represented by formula II or III: ##STR1## wherein R.sup.3 to R.sup.12 are independently selected from the group consisting of hydrogen, hydroxy, sulfonate, or an alkyl of from 1 to 5 carbon atoms, and wherein at least two of such groups represent a hydroxy group.

Abstract: Certain radiation sensitive quinone compounds and nitrobenzylidene dyes in photothermographic elements, compositions and processes on exposure to activating radiation, release a species which catalyzes the reduction of silver salt oxidizing agents in the presence of non-light sensitive reducing agents upon heating. The elements, after imagewise exposure, are heated to develop the image.