Patent ID: 6498004
Filing Date: 2002-12-24
Classification: C07C,C07D,G03C,Y02P

Abstract:
A photographic element comprising at least one silver halide emulsion layer in which the silver halide is sensitized with a protected fragmentable electron donor compound of the formula (a), (b) or (c):&Dgr;âˆ’(t)mâˆ’XYâ€²â€ƒâ€ƒ(a) XYâ€²âˆ’(t)mâˆ’&Dgr;â€ƒâ€ƒ(b) &Dgr;âˆ’(t)mâˆ’XYâ€²âˆ’(t)mâˆ’&Dgr;â€ƒâ€ƒ(c) wherein &Dgr; is protective group that is eliminated during development of the photographic element, t is a timing group, m is an integer from 0 to 3, and XYâ€² is a fragmentable electron donor moiety in which X is an electron donor group and Yâ€² is a leaving proton H or a leaving group Y, with the proviso that if Yâ€² is a proton, a base, &bgr;âˆ’, is present in the emulsion or is covalently linked directly or indirectly to X, and wherein:1) Xâ€”Yâ€² has an oxidation potential between 0 and about 1.4 V; 2) the oxidized form of Xâ€”Yâ€² undergoes a bond cleavage reaction to give the radical Xâ€¢ and the leaving fragment Yâ€²; and 3) the radical Xâ€¢ has an oxidation potential &lE;âˆ’0.7V.