Exploring the design of superradiant J-aggregates from amphiphilic monomer units

Abstract

Excitonic chromophore aggregates have wide-ranging applicability in fields such as imaging and energy harvesting, however their rational design requires adapting principles of self-assembly to the requirements of excited state coupling....

Aggregates of Cyanine Dyes: When Molecular Vibrations and Electrostatic Screening Make the Difference

“…Cyanines are a widespread family of dyes, constituted by heterocyclic electron donors or acceptor groups linked through a polymethinic bridge. , Cyanines are of interest for several applications, including photovoltaics, bioimaging, − phototherapy, − optical devices, , sensors, etc. The tendency of cyanines to self-organize in aggregates is known since 1937 when Jelley and Scheibe first described the formation of cyanine aggregates in solution. , The photophysics of cyanine aggregates strongly depends on the details of the molecular packing, which, in turn, are affected by several factors, including the length of the polymethinic bridge, the presence of non conjugated alkyl chains and their length, the environment (including the presence of additives), etc. − The possibility to widely tune the material properties makes cyanine aggregates extremely promising for applications in photonics, electronics, imaging, etc. − A robust theoretical approach must therefore be developed to relate the intriguing properties of cyanine aggregates to their supramolecular structure.…”

“… 14 , 15 The photophysics of cyanine aggregates strongly depends on the details of the molecular packing, which, in turn, are affected by several factors, including the length of the polymethinic bridge, the presence of non conjugated alkyl chains and their length, the environment (including the presence of additives), etc. 16 − 21 The possibility to widely tune the material properties makes cyanine aggregates extremely promising for applications in photonics, electronics, imaging, etc. 22 − 26 A robust theoretical approach must therefore be developed to relate the intriguing properties of cyanine aggregates to their supramolecular structure.…”

Bright and Fast Emission from Robust Supramolecular J-Aggregate Nanostructures through Silica-Encapsulation

“…TDBC dye molecules are known to self-assemble into 2D sheets spanning several hundred nanometers in water–methanol blends. These J-aggregates exhibit distinctive optical features from their constituent dye molecules, including extremely narrow absorption and emission spectra, rapid radiative rates, extensive exciton delocalization and excitation migration. , In the past, the reported QYs for TDBC J-aggregates in solution were unsatisfactory, ranging from 5 to 49%, thus limiting their use in optical applications. − However, we recently demonstrated a QY of 82% with a 174 ps emissive lifetime through the purification of monomers prior to their self-assembly . Purification of monomers enables successful removal of impurities embedded in the densely packed J-aggregate supramolecular lattice, which can trap excitons and function as nonradiative recombination centers .…”

Regulating steric hindrances of perylenediimide to construct NIR photothermal J-aggregates with a large red-shift

“…The rational design of molecular J-aggregates presents a straightforward approach for acquiring agents with long-wavelength absorption. [16][17][18] However, considerable challenges persist in developing PTAs based on PDI J-aggregates, as the intense intermolecular π-π stacking effect that exists between large conjugated planes leads to a face-to-face arrangement (H-aggregates) of PDIs. 19 To date, various strategies have been employed, including the incorporation of steric hindrance groups, induction of hydrogen bonding, and space-confined assembly.…”