Mechanism of Excess Electron Transport in Liquid Hydrocarbons

Stable excess electrons have been recently observed in liquid hydrocarbons after suitable purification, but the mobilities indicated the existence of short-lived electron traps in the liquids. We have measured electron mobilities in mixtures of $n$-hexane and neopentane and find that the mobility is given accurately by an expression of the form $\mu ={\mu }_n\exp \left(\frac{-x_{h}E}{\mathrm{kT}}\right)$, where $x_h$ is the mole fraction of hexane. It is concluded that the trap cannot be a negative-ion state of a single molecule, but is instead a collective trap involving several fluid molecules.