ONE-ELECTRON REDUCTION OF 3,4,6,7,9,10-HEXAHYDRO-(1,8)-(2H,5H)-ACRIDINEDIONE - A PULSE-RADIOLYSIS STUDY

The radical anion formed on reaction of e(aq)(-) with acridinedione dy e (ADH) exhibits transient optical absorption bands at lambda(max) = 3 15, 460, and > 780 nm. The bimolecular rate constant for the reaction of e(aq)(-) with the dye was determined to be 2.7 x 10(10) dm(3) mol(- 1) s(-1). It is converted to (ADH(2)(.)) on protonation and showed an absorption band at 310 nm. At pH = 1, acetone ketyl radicals are obser ved to react with the dye with a bimolecular rate constant of 2.3 x 10 (8) dm(3) mol(-1) s(-1), and the transient optical absorption bands (l ambda(max) = 315, 540 nm) are assigned to (ADH(3))(.+). The radical an ion (ADH(.-)) is a strong reducing agent, with reduction potential = - 1.37 V vs NHE, and is able to undergo electron-transfer reactions with methyl viologen (MV2+) and p-nitroacetophenone (p-NAP) with bimolecul ar rate constants of 4.9 x 10(9) and 6.1 x 10(9) dm(3) mol(-1) s(-1), respectively.