Abstract: A novel silver halide photographic element which contains a nondiffusible complex capable of releasing a diffusible, photographically useful material is disclosed.Said nondiffusible complex becomes active for ligand exchange upon reduction under alkalin conditions to release a diffusible, photographically useful material, said complex being represented by the following formula: ##STR1## wherein La is a quadridentate ligand group; Lb is a didentate ligand group; BALL is a ballast group; PHOTO is a photographically useful material group; Y is a counter ion; and r is the number of counter ions necessary for neutralizing the electric charge on the CO(III) complex.

Abstract: A photographic element containing a nondiffusible metal complex capable of releasing a diffusible photographically useful group. The complex contains at least one poly-dentate ligand which contains the photographically useful group. The complex may be activated when reduced under alkaline conditions to release the photographically useful group.

Abstract: A photographic element comprising a support provided thereon with at least one light-sensitive silver halide emulsion layer containing a nondiffusible compound which receives at least one electron in an alkaline condition to release a photographically useful material and a nondiffusible electron donor or a precursor thereof having the following formula (I) or (II): ##STR1## wherein R.sup.1 represents hydrogen, an alkyl, an aryl or a heterocyclic group, R.sup.2 represents hydrogen, an alkyl, an aryl, a heterocyclic, an amino, a carbamide, a sulfonamide, a sulfamoyl, a carbamoyl or a ureido group, R.sup.3 and R.sup.4 each is hydrogen, --COR.sup.5, --SO.sub.2 R.sup.6 or --CSR.sup.7 wherein R.sup.5 and R.sup.6 each is a substituted or unsubstituted, respectively, alkyl, alkenyl, aryl, heterocyclic, alkylamino, alkyloxy, aryloxy, alkylthio, arylthio, alkyloxycarbonyl or aryloxycarbonyl group, and R.sup.7 is a substituted or unsubstituted alkyllamino or arylamino group, said R.sup.

Abstract: A photographic element for color diffusion transfer which includes a timing layer comprising a polymeric latex made up of (1) a conjugated diene monomer, (2) and ethylenically unsaturated acid monomer or salt, and (3) an ethylenically unsaturated monomer, which monomers are within certain percentage ranges.