Conductimetric Study of the Kinetics of Electrons in Pulse Irradiated n-Hexane and Cyclohexane at Room Temperature

Abstract

Measurements of the ion current following an electron pulse have given values of kr/µ(where kr is the ion recombination rate constant and µ the electron mobility) and Gµ(extrapolated to zero field) of 1.00(± 0.08)× 10–6 V cm and 1.13(± 0.05)× 10–2 cm2 V–1 respectively for n-hexane, and 0.91(± 0.07)× 10–6 V cm and 5.0(± 0.3)× 10–2 cm2 V–1 for cyclohexane. For n-hexane these and results obtained optically are consistent with kr= 6(± 1)× 1013 dm3 mol–1 s–1, G= 0.13 and µ= 0.09 cm2 V–1 s–1. Using µ= 0.35 cm2 V–1 for cyclohexane, kr= 1.93(± 0.14)× 1014 dm3 mol–1 s–1.

Rate constants for reaction of solutes with electrons in n-hexane have been measured which confirm those obtained optically. For electron reactions in cyclohexane k(e–+ S)× 10–11 dm3 mol–1 s–1 are 1.70, 43, 43, 33, 66, 90 and 3.5 when S is O2, CO2, CCl4, Ph2, diphenylanthracene, galvinoxyl and perfluoromethylcyclohexane respectively.

The mobility of the electron in n-hexane + alcohol mixtures is found to be unaffected until the alcohol concentration approaches 30 mmol dm–3 and at these low concentrations the electron reacts with the alcohol.