Spatial control of chirality in supramolecular aggregates

Abstract

Chirality is one of the most intriguing properties of matter related to a molecule’s lack of mirror symmetry. The transmission of chirality from the molecular level up to the macroscopic scale has major implications in life sciences but it is also relevant for many chemical applications ranging from catalysis to spintronic. These technological applications require an accurate control of morphology, homogeneity and chiral handedness of thin films and nanostructures. We demonstrate a simple approach to specifically transfer chirality to the model supramolecular system of J aggregates of the protonated form of tetrakis(4-sulfonatophenyl)-porphyrin by utilizing a soft lithography technique. This approach successfully allows the fabrication of an ordered distribution of sub-micrometric structures in precise and controllable positions with programmed chirality, providing a fundamental breakthrough toward the exploitation of chiral supramolecular aggregates in technological applications, such as sensors, non-linear optics and spintronic.

Giant intrinsic circular dichroism of prolinol-derived squaraine thin films

“…This effect can be utilized for light harvesting or emitting devices with direct detectivity 7 or emissivity 8 of CP light, respectively. Prerequisite are the availability of the enantiopure molecular components through an efficient and scalable synthesis, and the subsequent transfer of molecular chirality via supramolecular interactions to a sizable macroscopic scale 9 – 12 . Currently, (plasmonic) metamaterials 13 , which incorporate structures with characteristic lengths comparable to the wavelength of light, surpass natural chiral materials regarding their chiroptical effects.…”

Chiral Supramolecular Nanoarchitectures from Macroscopic Mechanical Rotations: Effects on Enantioselective Aggregation Behavior of Phthalocyanines

“…These studies have attracted considerable attention for the following reasons: 1) the vortex motion induced by Earth's rotational motion, that is, the Coriolis effect, which may be one explanation for the homochirality of life—the biased distribution of l ‐amino acids and d ‐sugars—in addition to circularly polarized light induced asymmetric photochemical reactions, and magnetic field effects on asymmetric photochemical reactions, and 2) the possibility for novel absolute asymmetric synthetic methods without the need for chiral catalysts . Therefore, vortex‐motion‐based control of supramolecular chirality has been intensively investigated by the use of macroscopic mechanical rotations, such as magnetic stirrers . At first, Ohno et al.…”

Influence of Magnetic Micelles on Assembly and Deposition of Porphyrin J-Aggregates

“…These latter showed significant improvements toward technological applications, even if the uniformity and spatial control of the local handedness of chiral self-assembled systems on a surface is still a fundamental open challenge. In this framework, we already investigated the self-assembly of the achiral water soluble 5,10,15,20-tetrakis-(4-sulfonatophenyl)-porphyrin (TPPS) into chiral aggregates on a substrate by combining a wet lithographic method with the local induction of specific chirality imprinted by a chiral templating agent [32]. It is well known that the diacid form of this porphyrin in solution under the opportune experimental conditions is able to self-organize into highly ordered chiral J-aggregates with or without the assistance of chiral species [33][34][35].…”