Self-assembled thermoreversible gels of nonpolar liquids by racemic propargylic alcohols with fluorinated and nonfluorinated aromatic rings.
The synthesis and colloidal study of a new class of low molecular weight organogelators is reported. Racemic propargylic alcohols with perfluoroaryl and nonfluorinated aryl rings are capable of forming gels in alkane liquids and/or silicone oil. A full colloidal characterization of alkane gels prepared from (R/S)-1-pentafluorophenyl-3-phenylprop-2-yn-1-ol [(R/S)- 1] was conducted, including both structural [optical microscopy, scanning electron microscopy (SEM), powder X-ray diffraction (XRD), attenuated total reflectance infrared spectroscopy (ATR-IR)] and thermal stability [differential scanning calorimetry (DSC)] studies. A model of the organization of gelator molecules within gel fibers has been proposed primarily based on the correlation of diffraction data for the powder XRD pattern of a gel and a simulated powder pattern from a sublimed crystal of the gelator. Furthermore, structural requirements for propargylic alcohol gelators were investigated by subjecting derivatives with modified structures to gelation tests. An enantiomerically enriched sample [(R)- 1, 83% ee] fails to entrap the solvent under conditions where the racemate successfully forms a gel. The remaining racemic derivatives (with p-alkoxy or p-alkyl substituents on the nonfluorinated arene) form gels or partial gels in silicone oil and in some alkane preparations.
Borges
Ashleigh R
AR
Department of Chemistry and Biochemistry, James Madison University, Harrisonburg, Virginia 22807, USA.
Hyacinth
Marilise
M
Lum
Michelle
M
Dingle
Clayton M
CM
Hamilton
Paris L
PL
Chruszcz
Maksymilian
M
Pu
Lin
L
Sabat
Michal
M
Caran
Kevin L
KL
D000480:Alkynes / Q000138:chemical synthesis / Q000737:chemistry*; D018360:Crystallography, X-Ray; D017611:Fluorine Compounds / Q000737:chemistry*; D005782:Gels / Q000737:chemistry; D007536:Isomerism; D008855:Microscopy, Electron, Scanning; D008958:Models, Molecular; D015394:Molecular Structure; D044367:Phase Transition; D020005:Propanols / Q000138:chemical synthesis / Q000737:chemistry*; D013057:Spectrum Analysis; D013696:Temperature
D000480:Alkynes; D017611:Fluorine Compounds; D005782:Gels; D020005:Propanols; C028255:propargyl alcohol