Photographic material suited for use in diffusion transfer photography

A photographic silver halide material comprising a support carrying at least one unexposed alkali-permeable silver halide hydrophilic colloid emulsion layer which contains therein a quinonoid compound having a para- or ortho-quinonoid nucleus and which compound is immobile in an alkali-permeable colloid medium when contacted with an alkaline liquid and which contains a photographically useful group and a ballast group, wherein said compound is capable of being reduced by a silver halide developing agent at a rate slower than that of image-wise developable silver halide in the photographic material and in reduced state is capable of releasing said photographically useful group under alkaline conditions, characterized in that said quinonoid compound corresponds to one of the following formulae (A) or (B):

• ##STR26## wherein:
• each of (Nuox).sup.1 and (Nuox).sup.2 (same or different) represents an oxidized nucleophilic group,
• Z represents a bivalent atom or a bivalent atomic group, which is electro-negative with respect to the carbon atom carrying R.sup.1 and R.sup.2,
• Q together with the group Z represents a releasable photographically useful group,
• Y.sup.1 and Y.sup.2 together represent the necessary atoms to close a p-quinonoid ring substituted with (a) directly linked monovalent organic ring or ring system substituent(s) having aromatic character,
• Y.sup.3 represents the necessary atoms to close an o-quinonoid ring substituted with (a) directly linked monovalent organic ring or ring system substituent(s) having aromatic character, and
• each of R.sup.1 and R.sup.2 (same or different) represents hydrogen or a hydrocarbon group, at least R.sup.1, R.sup.2 or a substituent on the quinonoid ring being or containing a ballasting group X of sufficient size to keep said compound immobile in an alkali-permeable layer of the photographic material when said layer is contacted with an alkaline liquid, the monovalent organic ring or ring system substituent having aromatic character being a monovalent organic substituent derived from an organic substance having only carbon atoms or carbon atoms and (a) heteroatom(s) linked to each other forming a ring or ring system stabilized by resonance due to overlapping .pi.-orbitals of alternating double bonds or of double bonds and (a) lone pair p-orbital(s) of (a) hetero atom(s), whereby the Huckel rule is obeyed, said rule stating that (4n+2) electrons should be present in the overlapping orbitals, n being any positive integer here not including zero.