Imaging element containing a blocked photographically useful compound

A method of image formation comprising the step of developing an imagewise exposed imaging element comprising an imaging layer having associated therewith a compound of Structure I:

• 34
• wherein:
• PUG is a photographically useful group;
• LINK 1 and LINK 2 are linking groups;
• TIME is a timing group;
• l is 0 or 1;
• m is 0, 1, or 2;
• n is 0 or 1;
• Y is C, N, O or S;
• X is a substituted or unsubstituted aryl group or an electron-withdrawing group;
• W is hydrogen, halogen, or a substituted or unsubstituted alkyl, cycloalkyl, aryl or heterocyclic group, or W can combine with T or R12 to form a ring, w is 0 to 3 when Y is C, w is 0-2 when Y is N, and w is 0-1 when Y is O or S, when w is 2, the two W groups can combine to form a ring, and when w is 3, two W groups can combine to form a ring or three W groups can combine to form an aryl group or a bicyclic substituent;
• R12 is hydrogen, or a substituted or unsubstituted alkyl, cycloalkyl, aryl or heterocyclic group or R12 can combine with T to form a ring;
• T is a substituted or unsubstituted alkyl cycloalkyl, aryl or six-membered heterocyclic group, t is 0, 1, or 2, with the proviso that when X is a cyano group, t is 1 or 2, when X is a sulfono group, t is 1 or 2, a and l are each 1, and m and n are each 0, and when t is 2 the two T groups can combine to form a ring;
• a is 1 or when X is divalent a is 1 or 2;
• and
• b is 1 when X is divalent and 0 when X is monovalent.