Kinetic Control of Chirality in Porphyrin J-Aggregates

Abstract

Detailed kinetic investigations demonstrate the fundamental role of kinetic parameters in the expression and transmission of chirality in supramolecular systems. The rate of the aggregation process leading to the formation of J-aggregates strongly affects the size of these nanoassemblies and the chiral induction.

Chiral tetrakis(4-carboxyphenyl)porphyrin aggregates induced by enantiomeric dibenzoyl tartaric acids at the air–water interface

“…A c c e p t e d M a n u s c r i p t 7 Fig. 3 shows the FTIR spectra for the LB films of TCPP and its mixtures with D-/L-DBTarA together with those of the TCPP and DBTarA compounds in solid powders, which revealed the following features.…”

“…More recently, however, with the development of molecular self-assembling techniques, many effects have influenced the design and construction of chiral supramolecular complex structures with the use of achiral molecules induced by special chemical environments or by chiral compounds in solutions or at the interfaces. For instance, chiral porphyrin J-aggregates could be prepared in acid solutions and/or in the presence of cationic chiral templating reagents of octahedral metal complexes, simple amino acids or polylysines [6][7][8]. Similarly, chiral J-type aggregates of achiral perylene dianhydride dye have been created in acidic cetyltrimethylammonium bromide micelle solution, employing small molecules as the chiral auxiliary [9].…”

Spatial control of chirality in supramolecular aggregates

“…J-aggregates of porphyrins are largely studied as model systems12131415161718192021 due to their peculiar optical properties; e.g., large extinction coefficients, resonant light scattering16, light harvesting17 and giant third-order optical nonlinearities12. Chirality in these systems adds the possibility of interaction with circular polarized light and their investigation by circular dichroism.…”

“…mixtures of left-handed and right-handed chiral units) that can be easily biased through a variety of physical perturbations, such as vortex18, rotational and magnetic forces22, or using chemical chiral templates19. Kinetics of the assembling process control the eventual manifestation of chirality, both in bulk solution20 and in confined environments, such as in microemulsions20, or microfluidic conditions21.…”

“…This self-assembly process is highly hierarchical, and is driven by concentration, pH, ionic strength and/or presence of cationic species23. Chirality can be induced by chiral templating reagents into J-aggregates supramolecular assemblies that exhibit intense circular dichroism signals related to the specific handedness of the template1920. Characterization of the supramolecular aggregates in solution is reported in SI.…”