A new approach to molecular configuration applied to aqueous pore transport.

A cylindrical treatment of the configuration of small molecules in solution has been proposed. Cylindrical dimensions were obtained from Fisher-Hirschfelder molecular models, and these dimensions were used in an analysis of three sets of reflection coefficient values from the literature. The correlation between solute dimensions and the reflection coefficient was subjected to both statistical analyses and graphical examination, with particular emphasis given to parameter interdependence. The results consistently indicated a significant relation between the reflection coefficient and solute diameter. The dependence on diameter suggests a lengthwise orientation of solute within the membrane. Furthermore it is shown that this orientation is occurring within the aqueous region of the membrane, and thus this region has a structural characteristic which is responsible for the lengthwise orientation of solute.