Probing the mechanism of gelation and anion sensing capability of a thiazole based amide gelator: A case study

Abstract

In priori design of Low Molecular weight Gelators (LMWGs) based on the molecular structure is a challenging task and requires the hierarchy knowledge from single molecule packing to a supramolecular assembly in gelator fibers. A simple strategy to select and probe the packing of a molecule from a crystalline state to a semi solid gel state was undertaken in a Thiazole based amide, undecaneamido thiazole (Thz-9). The novel approach to select the promising molecule with gelation property was made using Small Angle Neutron Scattering (SANS) and Small Angle X-ray Scattering (SAXS) analysis of solid samples. Based on the preliminary examination of SANS/SAXS studies Thz-9 molecule was selected and subjected to study the packing of molecule in crystalline to a gel state. The sol-gel transition and variation of the molecular diameter of the supramolecular assembly of Thz-9 molecules in the various states were established using temperature dependent SANS study. Efforts were also directed to establish the relationship between the packing of molecules in single crystal structure to packing in xerogel (dried gel) using Powder X-ray Diffraction (PXRD). A potential application of Thz-9 as a fluoride ion sensor with good selectivity and sensitivity was established.