Is there any correlation between the Rf observed values and the structural features of phenylalanine,aspartic?

Question

Is there any correlation between the Rf observed values and the structural features of phenylalanine,aspartic?

Answer 1

Are you refering to normal Thin Layer chromatography?? If so then the structure of the two molecules does correlate to the Rf.

Aspartic acid is

COOHCH2CHNH2COOH

It is very polar. In Phenylalinine one of the COOH groups of the aspartic acid is replaced with a phenyl group. The phenyl group is much less polar than COOH, therefore phenylalinine is a less polar molecule than aspartic acid.

In Thin layer chromatography polarity of a moleclue strongly effects the Rf, for example, in a polar solvent the more polar molecule will move further up the plate, so structure affects the Rf.

See sources for structures of both of the amino acids.