Latent fingerprint visualization by 1,2-indanedione and related compounds: Preliminary results

A number of vicinal cyclic diketones, most of them belonging to the 1,2- indanedione series, have been prepared and tested as potential reagents for latent fingerprint development. Unsubstituted 1,2-indanedione and a number of its mono- and dimethoxy- derivatives exhibited excellent properties as fluorogenic reagents for latent prints on paper. Structural modifications, such as substitutions at position 3, omission of the benzene ring or increase of the five-membered to a six-membered ring, considerably reduced this activity. Quite surprisingly, benzo[f]indane-1,2-dione, which was synthesized for the first time in this work, was significantly inferior to 1,2- indanedione as a fingerprint reagent. Even at this stage, before optimization of the reaction conditions, it can be said that some 1,2-indanediones are at least as sensitive as DFO. Their solubility in nonpolar solvents and relative ease of preparation are further advantages. It is the authors' opinion that 1,2-indanedione itself may soon become a practical fingerprint reagent.