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An investigation, based on absorption and circular dichroism spectroscopy, was carried out on assemblies formed in water upon the interaction of heteroaggregates, composed of dyes (Congo Red or Evans Blue) and cetyltrimethylammonium bromide (CTAB), with four enantiopure phopshocholines (DMPC, DPPC, DOPC, and POPC) characterized by the same polar head and different hydrophobic tails. The results show that the nature of the lipid as well as the concentration ratios influence sensitively the absorption and chiroptical properties of the supramolecular structure. Intriguingly, the transfer of chirality from the lipid to the assembly may be triggered or not, depending on the nature of the lipid hydrophobic chain. These findings confirm the fundamental role of hydrophobic interactions in the transcription of chirality from molecules to complex architectures. [ABSTRACT FROM AUTHOR]

An absorption and circular dichroism spectroscopies investigation was carried out on the heteroaggregates formed in water upon the interaction of Chicago Sky Blue with four different cationic surfactants derived from ephedrine and pseudoephedrine and featuring hydrophobic tails of different length. The chirooptical features of the heteroaggregates indicate that hydrophobic interactions control the transcription of the chiral information from the surfactant to the supramolecular architectures they form with the dye. In fact, surfactants characterised by the same stereochemistry and by different length of the hydrophobic tails mediate the selection of the enantiomers of the same chiral topological arrangement. [ABSTRACT FROM AUTHOR]

In this work a combined theoretical and experimental approach was used to elucidate and describe at the molecular level the basic interactions that drive the transfer of the chiral information from chiral surfactant molecules to dye/surfactant assemblies. It was found that both hydrophobic interactions and relative concentrations strongly influence the chiroptical features of the heteroaggregates. In particular it was observed that, depending on the length of the surfactant hydrophobic chain, the chiral information is transferred to the dye by stabilizing an enantiomer either of a chiral conformer or of a chiral topological arrangement. These findings underline the role of hydrophobic interactions in the transfer of chirality and provide an example of the potential of in silico simulations for providing an accurate description of the process of chirality propagation. [ABSTRACT FROM AUTHOR]

Abstract: The chirality of micellar aggregates formed by surfactants derived from l-proline was investigated by using two chiral biphenylic derivatives as probes of chirality. The investigation carried out by 1H NMR, circular dichroism, and HPLC on chiral phase demonstrates that chiral recognition may occur in sites of the aggregates far from the head-group stereogenic centers and it is due to interaction with a whole region of the aggregate rather than with a single monomer in the aggregate. Subtle changes of the structure of the monomer influence the aggregation properties of the surfactants and its expression of chirality. [Copyright &y& Elsevier]

The article studies the aggregation of amphiphilic chiral cationic porphyrin derivatives in the presence of chiral aggregates of the anionic, that is, negatively charged, chiral analogue 2H2 using ultraviolet-visible, circular dichroism and resonance light scattering spectroscopy techniques. According to the authors, the electrostatic-templated heteroaggregation of porphyrin derivatives induces a remarkable amplification of the chirality of the final suprastructure.