title: The effect of hydrogen-bonds of amino acid-derived diacetylene by photopolymerization in supramolecular hydrogels.
abstract: Amino acids derived diacetylene hydrogelators 1 and 2 which have glycine or alanine moiety as head group were synthesized by several steps. The influences on the hydrogen-bonding interaction between amino acids moieties of hydrogelators in the polymerization by UV irradiation were investigated. The glycine-based hydrogel 1 resulted in the generation of stronger absorption peak at 540 nm at room temperature by UV-irradiation. Interestingly, the red color of the glycine-based diacetylene hydrogel 1 was gradually changed into blue color by decreasing temperature. Finally, the absorption band with 640 nm of glycine-based diacetylene hydrogel 1 showed at 77 K. On the other hand, the alanine-based hydrogel 2 had no significant color change at 77 K. These different color changes between the hydrogels 1 and 2 are attributed to the strong intermolecular hydrogen-bonding interaction between glycine moieties of the hydrogelator 1, as confirmed by FTIR observation. These results indicate that the hydrogen-bonding strength of the self-assembled hydrogel is a strong influence on the degree of polymerization.
authors: Department of Chemistry and Research Institute of Natural Sciences and Environmental Biotechnology National Core Research Center, Gyeongsang National University, Jinju 660-701, Republic of Korea.
authors: Sung Ho
authors: SH
authors: Jung
authors: Hyejin
authors: H
authors: Lee
authors: Won Seok
authors: WS
authors: Han
authors: Jong Hwa
authors: JH
authors: Jung
mesh_terms: D000480:Alkynes / Q000737:chemistry* / Q000528:radiation effects; D000596:Amino Acids / Q000737:chemistry*; D003460:Crystallization / Q000379:methods*; D020100:Hydrogels / Q000138:chemical synthesis* / Q000528:radiation effects; D006860:Hydrogen Bonding; D046911:Macromolecular Substances / Q000737:chemistry / Q000528:radiation effects; D008422:Materials Testing; D008968:Molecular Conformation / Q000528:radiation effects; D049329:Nanostructures / Q000737:chemistry* / Q000528:radiation effects / Q000648:ultrastructure; D010316:Particle Size; D011108:Polymers / Q000138:chemical synthesis / Q000528:radiation effects; D013499:Surface Properties / Q000528:radiation effects; D014466:Ultraviolet Rays
chemical_list: D000480:Alkynes; D000596:Amino Acids; D020100:Hydrogels; D046911:Macromolecular Substances; D011108:Polymers