L-phenylalanine Derivatives Synthesis And Build A Two-component Organic Gel

A series of mono-chain L-benzedrine acid derivatives were synthesized. Two-component organogels formed by L-benzedrine acid derivatives and aliphatic amines and double amine were performed by scanning electron microscope (SEM), the Fourier transform infrared spectroscopy (FT-IR), variable-temperature 1H NMR spectra and small angle X-ray diffraction (SA-XRD). Their gelation abilities, morphologies as well as self-assembly behaviors in gel state were investigated in detail. Furthermore, a rational mechanism of the formation of organogels was proposed on base of our studies. We obtained some creative results, which were outlined as follows:(1) Firstly, the formation of two-component organogels was investigated in organogelation systems consisting of mono-chain L-benzedrine acid derivatives and aliphatic amines (molar ratior=1:1) and their gelation properties in various organic solvents were tested. SEM images showed that two-component organogelators with different alkyl chain possessed similar morphologies, which were made of fine and long fibers. FT-IR spectrum demonstrated that the organogelation occurs through the formation of an organic salt compound by an acid–base interaction in addition to hydrogen bonding and van der Waals interaction. XRD patterns of xerogels implied that the arrangement of organogelator molecules in gel state were well-ordered. In addition, the long spacing (Dn) is smaller than evaluated molecular lengths (Ln) summation of L-benzedrine acid and aliphatic amines by optimized CPK model, but much larger than the length of one molecule, demonstrating that the gel aggre-gates consist of a repeating bilayer unit. 1H NMR spectra indicated that the amide group of L-benzedrine acid derivatives participates in the intermolecular hydrogen-bond interaction in the gel state. From the analysis and results of SEM, FT-IR, XRD, it can be deduced that organogelator molecules took advantage of acid–base interaction in addition to hydrogen bonding and van der Waals interaction, then such aggregates extended to become fibers, which developed a rigid three-dimensional network superstructure and finally immobilized the liquids.(2) The second part focuses on the two-component organogels formed by L-benzedrine acid derivatives and double amine (molar ratior=2:1). Their gelation properties in various organic solvents were tested by SEM, FT-IR, XRD. We can deduced two-component organic gelators could self-assemble into aggregates of fiber and filmlike lamellae structures through acid-base interaction and intermolecular hydrogen bonding, which are juxtaposed and interlocked by van der waals interaction and finally gelate the organic liquids.