Naslov
Biphenyl Bis(amino alcohol) Oxalamide Gelators: Complex Gelation Involving Coupled Equilibria, Central-to-Axial Chirality Transfer, Diastereoisomer Interconversion, and Self- Sorting

Autori
Portada, Tomislav ; Molčanov, Krešimir ; Šijaković Vujičić, Nataša ; Žinić, Mladen

Izvornik
European journal of organic chemistry (1434-193X) (2016), 6; 1205-1214

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
organogelators; chirality; chirality transfer; axial chirality

Sažetak
Chiral gelators 3 and 4, with two valinol- or leucinoloxalamido arms attached to the 2, 2′- positions of the proatropisomeric biphenyl group, were prepared, and their gels were studied. Compound (R, R)-3 in the solution and gel states forms a mixture of major [(R, aR, R)-3] and minor [(R, aS, R)-3] diastereomers due to central-to-axial chirality transfer. 1H NMR studies of its toluene gel provide evidence of diastereomer interconversion and self- sorting, which results in exclusive incorporation of (R, aR, R)-3 into the gel network. Gels formed in the 10–3 M concentration range show an irregular Tg/concentration dependence, which is in contrast to those formed in the 10–2 M concentration range. The peculiar properties of the former gels may be explained by kinetic effects due to the presence of coupled equilibria comprising diastereomer interconversion and (R, aR, R)-3 self-assembly where the rate of gelation becomes dependent on the rate of formation of the gelling (R, aR, R)-3 from the nongelling (R, aS, R)-3.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

POVEZANOST RADA