Systematic Modulation of the Supramolecular Gelation Properties of Bile Acid Alkyl Amides
Kuosmanen, R., Puttreddy, R., Rissanen, K., & Sievänen, E. (2018). Systematic Modulation of the Supramolecular Gelation Properties of Bile Acid Alkyl Amides. Chemistry: A European Journal, 24 (70), 18676-18681. doi:10.1002/chem.201803151
Published inChemistry: A European Journal
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The self-assembly properties of nine bile acid alkyl amidebased low-molecular weight gelators (LMWGs) are studied in detail. Based on the results the number of hydroxyl groups attached to the steroidal backbone plays a major role in the gelation, although the nature of the aliphatic side chain modulates the gelation abilities as well. Of the 50 gel systems studied, 35 are based on lithocholic acid and 15 on cholic acid derivatives. The deoxycholic acid derivatives did not form any gels. The gelation commences primarily in aromatic solvents and the gels manifest typical fibrous or spherical morphologies. The 13C CPMAS NMR spectra measured from the crystalline materials and the corresponding wet organogels are analogous, suggesting that the chemical environments viz. the intermolecular interactions found in the organogels and in the crystalline state are similar. The single crystal X-ray structures of all nine bile acid amide derivatives studied revealed very similar molecular conformations in the solid state and gave insights into the possible intermolecular interactions in the gel state. ...