We recently reported the gelation ability and aggregation behavior of gelators whose structures contain three parts: aromatic, linker and cholesterol unit.  The gelators containing two cholesterol units linked to a biphenyl molecule by a flexible chain produced stronger and more stable gels than the gelators containing one cholesterol unit. These results are consistent with the hypothesis that one important driving force for aggregation of this type of molecules is the stacking of the cholesterol units.<br/>We report here the synthesis and gelation studies of two new gelators with structures that differ from the previous studies by replacing the cholesteryl unit with a methyl or ethyl moiety. The gelators 4-(7-methoxycarbonylheptyloxy) biphenyl (BBO8-Me) and 4-(7-ethoxycarbonylheptyloxy) biphenyl (BBO8-Et) were synthesized and studied. These gelators produced stable gels at lower concentration than the ones obtained from the gelators containing one or two cholesterol units. BBO8-Me forms 0.5 % (w/w) gels in n-octanol and n-butanol. BBO8-Et gels at 2% (w/w) in both solvents. The gels were characterized by absorption, fluorescence and circular dichroism spectroscopies.  SEM was used for the investigation of the morphology of the xerogels. Based on XRD data and molecular modeling, we propose packing modes for the formation of the organogelator aggregates.<br/>

Synthesis of novel biphenyl-ester gelators: The role of cholesteryl vs. methyl and ethyl esters on aggregation and gelation behavior

251st National Meeting (2016)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.