Simple Tyrosine Derivatives Act as Low Molecular Weight Organogelators


Aykent G., Zeytun C., Marion A., Ozcubukcu S.

SCIENTIFIC REPORTS, vol.9, 2019 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 9
  • Publication Date: 2019
  • Doi Number: 10.1038/s41598-019-41142-z
  • Journal Name: SCIENTIFIC REPORTS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Middle East Technical University Affiliated: Yes

Abstract

The gelation of L-Tyr(tBu)-OH in tetrahydrofuran (THF) was discovered serendipitously. It was noted that this tremendously low molecular weight (LMW) compound has the ability to gel a wide variety of organic solvents (e.g., N,N-Dimetylformamide (DMF), THF, butanol, toluene), even in very low concentrations (i.e., 0.1 wt/v% in DMF). Addition of bases such as NaOH and piperidine enhanced the gel property. By changing the side-chain protecting group to tert-butyldimethylsilyl (TBDMS), a fluoride ion-responsive organogel was also acquired. This new organogelator responded fluoride ion concentration as low as 0.2 ppm. Characterization of microstructures and gel behaviours were studied by powder X-Ray diffraction spectroscopy (XRD), transmission electron microscopy (TEM), rheological measurements and molecular dynamics (MD) simulations. Experimental observations and theoretical simulations consistently show a fibre-like structure of the gel, in which the organogelator molecules are held together via a dense network of hydrogen bonds, and via van der Waals interactions between hydrophobic groups.