Isomaleimide and isophthalimide derivatives of chromophors

A compound selected from the group consisting of:

• ##STR7## wherein R represents an organic chromophoric group exhibiting fluorescence, luminescense chemoluminesence or absorption properties;
• R.sub.1, R.sub.2, R.sub.3 and R.sub.4 individually represent hydrogen or halogen, or alkyl, aryl, hydroxyl, carboxyl, alkyl, or aryl-substituted or unsubstituted amino groups, nitro or sulfonic groups;
• X and Y represent hydrogen or halogen, or alkyl, aryl, alkoxy, aryloxy, carboxyl, hydroxyl, alkyl or aryl-substituted or unsubstituted amino groups, nitro or sulfonic groups, and Z represents an organic substrate free of chromophoric groups, and wherein ##STR8## is derived from a primary or secondary amine.