01786nas a2200205 4500008004100000022001400041245012000055210006900175260000900244300001600253490000800269520105100277100001901328700002701347700001701374700001601391700003001407700001701437856012601454 2016 eng d a0002-786300aCounteranion driven homochiral assembly of a cationic C-3-symmetric gelator through ion-pair assisted hydrogen bond0 aCounteranion driven homochiral assembly of a cationic C3symmetri cSEP a11113-111160 v1383 a
The helical handedness in achiral self-assemblies is mostly complex due to spontaneous symmetry breaking or kinetically controlled random assembly formation. Here an attempt has been made to address this issue through chiral anion exchange. A new class of cationic achiral C-3-symmetric gelator devoid of any conventional gelation assisting functional units is found to form both right-and left-handed helical structures. A chiral counteranion exchange-assisted approach is successfully introduced to control the chirality sign and thereby to obtain preferred homochiral assemblies. Formation of anion-assisted chiral assembly was confirmed by circular dichroism (CD) spectroscopy, microscopic images, and crystal structure. The X-ray crystal structure reveals the construction of helical assemblies with opposite handedness for (+)- and (-)-chiral anion reformed gelators. The appropriate counteranion driven ion-pair-assisted hydrogen-bonding interactions are found responsible for the helical bias control in this C-3-symmetric gelator.
1 aMaity, Arunava1 aGangopadhyay, Monalisa1 aBasu, Arghya1 aAute, Sunil1 aBabu, Sukumaran, Santhosh1 aDas, Amitava uhttp://library.ncl.res.in/content/counteranion-driven-homochiral-assembly-cationic-c-3-symmetric-gelator-through-ion-pair