Cleavable aromatic nitro compounds
AssigneeEastman Kodak Company
InventorsJerald C. Hinshaw, Richard P. Henzel
Life of this patent
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Abstract
Aromatic nitro compounds are disclosed where the aromatic ring contains electron-withdrawing groups and said aromatic nitro compound is capable of undergoing intramolecular nucleophilic displacement after reduction of the nitro group. The compounds are especially useful in photographic elements where an image dye-providing material or a photographic reagent are released upon cleavage from the compound.
Claims24
A photographic element comprising a support having thereon at least one layer containing a silver halide having associated therewith a compound of the formula:
- ##STR24## where A represents a group containing the atoms necessary to form a 5- to 6-membered aromatic ring with the remainder of said formula;
- W is an electron-withdrawing group having a positive Hammett sigma value;
- R.sup.2 is a hydrogen atom, an alkyl group or an aryl group;
- R.sup.1 is a bivalent organic group containing from 1-3 atoms in the bivalent linkage;
- m and q are positive integers of 1 or 2;
- p is a positive integer of 1 or greater, and p is 1 only when A contains an aromatic 'onium group, and when p is 2, the substituent [(R.sup.2).sub.q-1 W] is ortho or para to the nitro group on said formula;
- E and Q provide an electrophilic cleavage group where E is an electrophilic center, and Q is a bivalent group providing a monoatom linkage between E and X.sup.1 wherein said bivalent group is a nonmetallic atom with a negative valence of 2 or 3 from Groups VA and VIA of the periodic table;
- n is an integer of 1-3;
- and X.sup.1, together with Q, is either an image dye-providing material or a photographic reagent.
An article of manufacture comprising a support having thereon an alkali-permeable layer containing a compound having the formula:
- ##STR27## where A represents a group containing the atoms necessary to form a 5- to 6-membered aromatic ring with the remainder of said formula;
- W is an electron-withdrawing group having a positive Hammett sigma value;
- R.sup.2 is a hydrogen atom, an alkyl group or an aryl group;
- R.sup.1 is a bivalent organic group containing from 1-3 atoms in the bivalent linkage;
- m and q are positive integers of 1 or 2;
- p is a positive integer of 1 or greater, and p is 1 only when A contains an aromatic 'onium group, and when p is 2, the substituent [(R.sup.2).sub.q-1 W] is ortho or para to the nitro group on said formula;
- E and Q provide an electrophilic cleavage group where E is an electrophilic center, and Q is a bivalent group providing a monoatom linkage between E and X.sup.1 wherein said bivalent group is a nonmetallic atom with a negative valence of 2 or 3 from Groups VA and VIA of the periodic table;
- n is an integer of 1-3;
- and X.sup.1, together with Q, is either an image dye-providing material or a photographic reagent.
Dependencies are inferred from the claim text.