The Production of the Indole Radical Anion during Gamma-Radiolysis of MTHF Glasses at 77 K: Absorption and EPR Spectroscopic Properties

Abstract

Spectrophotometric studies of MTHF (2-methyltetrohydrofuran) solutions at 298 and 77.degree. K show that indole exists as an undimerized, nonaggregated form in the concentration range 10-4-10-1 M. Estimation of electron-scavenging efficiency by indole in irradiated 77.degree. K glasses by optical and EPR analyses results in a scavenging constant of 33 .+-. 7 M-1. The simple radical anion produced on electron attachment by indole possesses absorption maxima at 360 (.epsilon.360 [extinction coefficient at 360 nm] = 4.1 .times. 103 M-1 cm-1) near 700, 1000 and 1200-1500 nm, and a simple EPR spectrum consisting of a singlet at g [gauss] = 2.002 and a linewidth of less than 20 g.