Firstly, it enables sample analyses both in solution and hydrogel phases, instead of xerogels whereby bulk water was removed. Secondly, it is possible to select the most appropriate excitation wavelength in the UV-range to enhance aromatic signals, such as those of the Phe benzene ring. In this case, upon excitation at 213 nm, it was possible to observe that all 1-4 gels in their hydrated state displayed enhanced peaks at 1584 and 1604 cm -1 , corresponding to C-C stretching modes of the Phe side chain (Fig. ). In the case of compound 1, it was possible to monitor the crystallization process, acquiring spectra in operando whilst heating from 298 K to 372 K. The phase transformation was accompanied by sharpening of the aromatic signals and further rising of the peak at 1692 cm -1 (Fig. ). This Raman mode corresponds to the amide I signal of the supramolecular state whereby the network of H-bonds is present already in the hydrated gel, and further extends during crystallization, confirming analogous packing modes in both states.