Characterization of a chiral low molecular weight gelator in gel state using various circular dichroism methods

Circular dichroism(CD) is usually used to study supramolecular chirality. With the development of CD methods, diffuse transmission CD(DTCD) and diffuse reflectance CD(DRCD) have been developed. However, the relationship among CD, DTCD and DRCD has not been well-studied. A chiral low molecular weight gelator was synthesized, which can result in a transparent physical gel in deionized water. The field-emission electron microscopy images show that the gel is able to self-assemble into left-handed helical fibers. The CD and DTCD spectra are almost identical, but they partially differ from the DRCD spectrum. Based on the TD-DFT calculated CD spectrum, the DRCD spectrum is shown to be more accurate.