J‐Aggregates: From Serendipitous Discovery to Supramolecular Engineering of Functional Dye Materials

Abstract

J-aggregates are of significant interest for organic materials conceived by supramolecular approaches. Their discovery in the 1930s represents one of the most important milestones in dye chemistry as well as the germination of supramolecular chemistry. The intriguing optical properties of J-aggregates (in particular, very narrow red-shifted absorption bands with respect to those of the monomer and their ability to delocalize and migrate excitons) as well as their prospect for applications have motivated scientists to become involved in this field, and numerous contributions have been published. This Review provides an overview on the J-aggregates of a broad variety of dyes (including cyanines, porphyrins, phthalocyanines, and perylene bisimides) created by using supramolecular construction principles, and discusses their optical and photophysical properties as well as their potential applications. Thus, this Review is intended to be of interest to the supramolecular, photochemistry, and materials science communities.

A single-residue substitution inhibits fibrillization of Ala-based pentapeptides. A spectroscopic and molecular dynamics investigation

“…(iii) The overlap between aromatic rings may occur in a plane-to-plane (H-type) or an edge-to-edge (J-type) orientation, driving the self-assembly process toward a specic geometry. 4 Aromatic/aromatic interactions have been shown to induce the self-assembly of pentapeptide derivatives in water to form nanobers and supramolecular hydrogels. 5 More strikingly, also the Phe-Phe dipeptide, an important structural motif of the Ab peptide, i.e.…”

A stochastic reorganizational bath model for electronic energy transfer

“…J-aggregates, [82][83][84] named after Jelley, are relatively ordered molecular arrays whose transition dipoles are arranged in such a way that large exciton delocalization is present in the low-energy excitation bands. They have technologically relevant optical properties such as a narrow absorption band that exhibits a large absorption intensity at the expense of a large number of quasi-dark excited states.…”

Highly fluorescent complexes with 3-isocyanoperylene and N-(2,5-di-tert-butylphenyl)-9-isocyano-perylene-3,4-dicarboximide

“…1,2 Due to these remarkable properties, PDIs are materials that, in additon to their use as industrial important pigments, 3 have been utilized or explored in other various optical and electronic applications, 4,5,6,7,8 or for liquid crystals, 9 and for highly fluorescent J-aggregates. 10 Also, the incorporation of metal centers to PDI structures at the imide region or at bay positions offers the possibility to modify the photochemistry and photophysics, and as a result their potential applications. 11 We have published platinum organometallic complexes of perylene and perylene monoimide (N-(2,5-di-tertbutylphenyl)perylene-3,4-dicarboximide, PMI) with Pt σ-bonded directly to the perylene core, 12 and have found that, in spite of the fact that attaching directly metal centers to aromatic cores of organic chromopheres is usually very detrimental, the coordination of Pt has only a moderate quenching effect on the fluorescence (our organoplatinum derivatives kept 70-80% of the fluorescence intensity of the mother organic molecule).…”