Silver halide photographic element

摘要

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: 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.