We find that increasing the extractant chain length also reduces T C , which is consistent with the widely reported impact of extractant chain length for malonamides and other classes of extractant. As with the role of diluent chain length above, this indicates the phase stability of simple binary mixtures can provide insight into more complex organic phases. However, another change in structure along the room temperature isotherm occurs as T C is lowered: the correlation length maximum moves to lower extractant volume fractions.