Mobile solvent holes in cyclohexane can be reversibly trapped by methylcyclohexane (Delta G degrees = -0.11 eV), 1,1-dimethylcyclopentane (Delta G degrees = -0.20 eV), trans-1,2-dimethylcyclopentane (Delta G degrees = -0.25 eV), and 2,3-dimethylpentane (Delta G degrees = -0.21 eV). The two dimethylcyclopentanes are identified as "special" impurities responsible for bimodal scavenging kinetics of the solvent holes. The mechanism of the reversible trapping is shown to be charge transfer. Neither the difference in the ionization potentials Delta IPliq of the solvent and the solute, nor the driving force Delta G degrees of the scavenging reaction are found to correlate with the rate constants of this charge transfer. The proposed explanation is that these rate constants are controlled by the height of the activation barrier that can be estimated from the difference in the vertical IP for the solute and adiabatic IP of the solvent. The correlation of the rate constants with this difference suggests that electron transfer involving mobile holes occurs much faster than the relaxation time of the solute radical cations. This work gives the first data on adiabatic IP for saturated hydrocarbons in solution.