Template-assisted strategies are widely used to fabricate nanostructured materials. By taking these strategies a step forward, herein we report the design of two chiral plasmonic nanostructures based on Au nanoparticle (NP) assemblies organized in clockwise and anticlockwise directions, having opposite response to circularly polarized light. The chiral plasmonic nanostructures are obtained by growing Au NPs on chiral templates based on d- and l-forms of alanine functionalized phenyleneethynylenes. Interestingly, Au NP assemblies show mirror symmetrical electronic circular dichroism (ECD) bands at their surface plasmon frequency originating through their asymmetric organization. Upon increasing the temperature, the chiral templates dissociate as evident from the disappearance of their ECD signal. The profound advantage of the thermoresponsive nature of the templates is employed to obtain free-standing chiral plasmonic nanostructures. The tilt angle high-resolution transmission electron microscopic measurements indicate that the NP assemblies, grown on a template based on the d-isomer, organize in clockwise direction (P-form) and on l-isomer in anticlockwise direction (M-form). The inherent chirality prevailing on the surface of the template drives the helical growth of the Au NPs in opposite directions. Experimental results are rationalized by a model which accounts for the large polarizability of Au NPs. The large polarizability leads to large oscillating dipole moments whose effects become prominent when interparticle distances are comparable to the particle size.

Chiroptical properties of supramolecular assemblies originate through the asymmetric coupling of molecular transition dipole moments. Herein, we report a joint experimental and theoretical investigation to understand the influence of intermolecular interactions on chiroptical properties, particularly during the early stages of self-assembly. In this regard, phenyleneethynylene-based molecular systems appended with d- and l-isomers of phenylalanine have been synthesized with one as well as two electronic transitions in the spectral region of interest. When self-assembled, these molecules show distinctly different chiroptical properties with the right- and left-handed organizations, guided by the chirality of phenylalanines. The standard exciton approach explains the observation of a bisignated electronic circular dichroism signal in systems with a single transition but fails when applied to systems with two nearby transitions. Here, we present a generalized exciton approach that addresses the unusual chiroptical properties of systems with multiple transitions.

Single molecules that co‐transport cations as well as anions across lipid membranes are few despite their high biological utility. The elegant yet simple lipidomimmetic peptide design herein enables efficient HCl transport without the use of any external additives for proton transport. The carboxylic acids in the dipeptide scaffold provide a handle to append two long hydrophobic tails and also provide a polar hydrophilic carboxylate group. The peptide central unit also provides NH sites for anion binding. Protonation of the carboxylate group coupled with the weak halide binding of the terminal NH group results in HCl transport with transport rates of H+>Cl−. The lipid‐like structure also facilitates seamless membrane integration and flipping of the molecule. The biocompatibility, design simplicity, and potential pH regulation of these molecules open up several avenues for their therapeutic use.