Cyclic anhydride derivatives of chromophors

An adduct of an anhydride derivative of chromophors having the structural formula:

• ##STR7## wherein R is an organic chromophoric group exhibiting fluorescence, luminescence, chemiluminescence or absorption properties;
• Z is hydrogen, alkyl, aryl, or a heterocyclic group composed of carbon ,hydrogen and at least one of oxygen, nitrogen or sulfur, and wherein Z contains from 1 to 20 carbon atoms;
• each X contains 2 to 3 straight chain carbon atoms connecting the carbonyl groups;
• and Y is a divalent or polyvalent group comprised of carbon, hydrogen, and optionally oxygen, and contains up to 20 carbon atoms, and provides at least one single or multivalent alkyl, alkenyl, cycloalkyl, bicycloalkyl, bicyloalkenyl, aryl or carbonyl containing group bridging the carbonyl-containing moieties through one or ore of the carbon atoms of the X groups;
• L is nitrogen or oxygen;
• S is an organic substrate;
• and R' is hydrogen or alkyl, aryl or heterocyclic, of from 1 to 20 carbon atoms;
• and n is 0 or 1, with the proviso that when L is oxygen n is 0.