Supramolecular chirality induced by a weak thermal force

Mineo, Placido; Villari, Valentina; Scamporrino, Emilio; Micali, Norberto

doi:10.1039/c3sm52322e

Cited by 32 publications

(39 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…271 This uncharged porphyrin can spontaneously form self-assembled structures in water. Although PPeg4 is achiral, this molecule forms a chiral assembly in water.…”

Section: Solution Systems Micellesmentioning

confidence: 99%

Supramolecular Chirality in Self-Assembled Systems

2015

View full text Add to dashboard Cite

“…271 This uncharged porphyrin can spontaneously form self-assembled structures in water. Although PPeg4 is achiral, this molecule forms a chiral assembly in water.…”

Section: Solution Systems Micellesmentioning

confidence: 99%

Supramolecular Chirality in Self-Assembled Systems

2015

View full text Add to dashboard Cite

“…Apart from a few reports of symmetry breaking in solution [16,38,[56][57][58][59], the introduction of an interface is effective to control the intermolecular interactions, thereby affecting their self-assembly properties. The symmetry also can be broken at a confined two-dimensional (2D) surface/interface during the self-assembly of achiral building blocks [60].…”

Section: Symmetry Breaking In Self-assembly Systemsmentioning

confidence: 99%

Symmetry Breaking in Self-Assembled Nanoassemblies

Sang

Liu

2019

Symmetry

View full text Add to dashboard Cite

The origin of biological homochirality, e.g., life selects the L-amino acids and D-sugar as molecular component, still remains a big mystery. It is suggested that mirror symmetry breaking plays an important role. Recent researches show that symmetry breaking can also occur at a supramolecular level, where the non-covalent bond was crucial. In these systems, equal or unequal amount of the enantiomeric nanoassemblies could be formed from achiral molecules. In this paper, we presented a brief overview regarding the symmetry breaking from dispersed system to gels, solids, and at interfaces. Then we discuss the rational manipulation of supramolecular chirality on how to induce and control the homochirality in the self-assembly system. Those physical control methods, such as Viedma ripening, hydrodynamic macro- and micro-vortex, superchiral light, and the combination of these technologies, are specifically discussed. It is hoped that the symmetry breaking at a supramolecular level could provide useful insights into the understanding of natural homochirality and further designing as well as controlling of functional chiral materials.

show abstract

“…Te mperature gradients are produced by the different temperaturea long the cuvette's walls from top to bottom.S uch gradients generate the vortical motion of the aggregates alone www.chemeurj.org (withouts tirring) through the resulting chiral thermophoretic force. [40] The strength of the gradient, and its disappearance, is efficiently controlled by ah omemade thermostat system, and it has been checked that all samples (methods 1-3) are completely CD and LD silent in the absence of the temperature gradient, irrespective of the thermostat setting (see Figure S1, the Supporting Information). These data reveal the dramatic impact of minute temperature gradients (and soft chiral flows) on originally racemic supramolecular objects.…”

Section: Supramolecular Opticalactivity and Alignment Effectsmentioning

confidence: 99%

“…[19] Very few experimental and theoretical studies, [37][38][39] aimed at showing this correlation more quantitatively, exist. So far,a ll have dealt with hydrodynamic vortexes, that is,m acroscopic flows in the solution.H erein, we attempt to compare the effects of the hydrodynamic perturbation with that of the thermophoretic chiral force [40] (whicha cts only on the aggregates when the solventi sn ot stirred), and to determine experimentally the role of the aggregate constitution in supramolecular chirality response to these external fields. The chiroptical response of the different types of aggregates to the asymmetricf ield generated by hydrodynamic and thermophoretic forces is evaluated with circular (CD) and linear dichroism (LD) measurements.…”

Section: Introductionmentioning

confidence: 99%

Hydrodynamic and Thermophoretic Effects on the Supramolecular Chirality of Pyrene‐Derived Nanosheets

Micali

Vybornyi

Mineo

et al. 2015

Chemistry A European J

Self Cite

View full text Add to dashboard Cite

Chiroptical properties of two-dimensional (2D) supramolecular assemblies (nanosheets) of achiral, charged pyrene trimers (Py3 ) are rendered chiral by asymmetric physical perturbations. Chiral stimuli in a cuvette can originate either from controlled temperature gradients or by very gentle stirring. The chiroptical activity strongly depends on the degree of supramolecular order of the nanosheets, which is easily controlled by the method of preparation. The high degree of structural order ensures strong cooperative effects within the aggregates, rendering them more susceptible to external stimuli. The samples prepared by using slow thermal annealing protocols are both CD and LD active (in stagnant and stirred solutions), whereas for isothermally aged samples chiroptical activity was in all cases undetectable. In the case of temperature gradients, the optical activity of 2D assemblies could be recorded for a stagnant solution due to migration of the aggregates from the hottest to the coldest regions of the system. However, a considerably stronger exciton coupling, coinciding with the J-band of the interacting pyrenes, is developed upon subtle vortexing (0.5 Hz, 30 rpm) of the aqueous solution of the nanosheets. The sign of the exciton coupling is inverted upon switching between clockwise and counter-clockwise rotation. The supramolecular chirality is evidenced by the appearance of CD activity. To exclude artefacts from proper CD spectra, the contribution from LD to the observed CD was determined. The data suggest that the aggregates experience asymmetrical deformation and alignment effects because of the presence of chiral flows.

show abstract

Supramolecular chirality induced by a weak thermal force

Cited by 32 publications

References 47 publications

Supramolecular Chirality in Self-Assembled Systems

Supramolecular Chirality in Self-Assembled Systems

Symmetry Breaking in Self-Assembled Nanoassemblies

Hydrodynamic and Thermophoretic Effects on the Supramolecular Chirality of Pyrene‐Derived Nanosheets

Contact Info

Product

Resources

About