The dyes have the general formulae: ##STR1## wherein the various substituents, R1 and R2 are each selected from hydrogen and {HEAD ~ a wide variety} of {TAIL ~ groups} such as lower alkyl, CN, halogen, and the like, R3 and R4 are each selected from hydrogen, lower alkyl, benzyl and phenyl, and Z represents the atoms necessary to complete a five or six membered ring 
The dyes have the general formulae : # # STR1 # # wherein the various substituents , R1 and R2 are each selected from hydrogen and { HEAD ~ a wide variety } of { TAIL ~ groups } such as lower alkyl , CN , halogen , and the like , R3 and R4 are each selected from hydrogen , lower alkyl , benzyl and phenyl , and Z represents the atoms necessary to complete a five or six membered ring
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