Derivatives of 1,10-Phenanthroline-5,6-quinone

Abstract

1,l0-Phenanthroline-5,6-quinone is prepared from 1,l0-phenanthroline via 5-nitro-1,l0-phenanthroline and 5-amino-1,l0-phenanthroline. It is converted by standard methods into 4,5-diazafluoren-9-one, 4,5-diazafluoren-9-ol,4,5-diazafluorene, and the new heterocyclic system dipyrido[3,2-a:2',3'-clphenazine. These four compounds each form a complex with cupric chloride. They thus represent a new series of chelating agents. By reaction with ethylene dibromide, dipyrido[3,2-a:2',3'-c]-phenaiine forms a diquaternary salt which is reduced in aqueous solution by a one-electron transfer to a highly coloured radical cation. Polarography experiments show that the reduction potential of the salt is -0.40 V against a standard calomel electrode.