Low-molecular-weight gelators based on N(alpha)-acetyl-N(epsilon)-dodecyl-L-lysine and their amphiphilic gelation properties.

A simple amphiphilic low-molecular-weight gelator based on L-lysine, N(alpha)-acetyl-N(epsilon)-lauroyl-L-lysine (1), its alkali metal salts [Na (2) and K (3)], and two-component gelators [1 and 2 and 1 and 3] were synthesized. Compound 1 had a good hydrogelation ability that formed a pure water gel at 2 g L(-1) (0.2 wt.%) and a saline gel at 4 g L(-1) (0.4 wt.%). Two-component compounds were able to form hydrogels in aqueous solutions containing alkali metal and alkali earth metal ions in addition to pure water and saline. Although 1 formed organogels in a few organic solvents, two-component compounds also functioned as a good organogelator. The FT-IR study indicated that the driving forces for the formation of supramolecular gels were hydrogen-bonding and hydrophobic interactions. Furthermore, the thermal properties of the hydrogels are discussed.