To probe whether dispersive attraction between the aliphatic peptoid bases is correlated with IFC formation we measured this property using a variety of approaches. Firstly, it is established that the number of methylene units in an alkane is necessarily correlated with the strength of attractive dispersive interactions and that branched alkanes also have lower boiling points compared to their linear isomers. In the context of amino acids, measured LogD partitioning values of N-acetyl-amino-acid amides of Leu and Ile have previously been shown to differ by 0.1 units, indicating that changes in architecture and in turn dispersive attraction do influence bulk properties. Indeed, in reversed phase high performance liquid chromatography, Nl exhibited the lowest retention time and therefore minimal ) and N-H bend (~1620 cm -1 ) for aromatic and aliphatic peptoid base salt crystals respectively, here the relative differences in absorption intensity and position demonstrate that the internal hydrogen bonding network in Nl, and to a lesser extent Nfe, differ most from the rest of the library; (H) carbonyl stretch and N-H bend regions for IFC structures formed by chloride salts of Leu-NH2 and Val-NH2 showing distinct absorption intensity and position verses the peptoids, both salts also form IFCs and so this implies that the phenomenon is not reliant on a specific hydrogen bonding network arrangement.