Organogels as scaffolds for excitation energy transfer and light harvesting

Abstract

The elegance and efficiency by which Nature harvests solar energy has been a source of inspiration for chemists to mimic such process with synthetic molecular and supramolecular systems. The insights gained over the years from these studies have contributed immensely to the development of advanced materials useful for organic based electronic and photonic devices. Energy transfer, being a key process in many of these devices, has been extensively studied in recent years. A major requirement for efficient energy transfer process is the proper arrangement of donors and acceptors in a few nanometers in length scale. A practical approach to this is the controlled self-assembly and gelation of chromophore based molecular systems. The present tutorial review describes the recent developments in the design of chromophore based organogels and their use as supramolecular scaffolds for excitation energy transfer studies.

Tailoring Colors by O Annulation of Polycyclic Aromatic Hydrocarbons

“…With respect to infinite graphene, PAHs show nonzero tunable bandgaps and are thus of use as chromophores in antennae7, 8, 9, 10, 11, 12 or emissive molecular architectures13, 14, 15, 16, 17, 18, 19 and in general in all optoelectronic applications requiring a tunable semiconducting material 6, 20. By exploiting organic synthetic tools,21, 22 one can tune the molecular HOMO–LUMO gap8 by 1) changing the size and edge of the carbon‐based aromatic framework; 2) varying the molecular planarity upon insertion of bulky substituents or bridging chains; 3) changing the aromatic properties of the constituent monomeric units; 4) varying the peripheral functionalization through the insertion of electron‐donating or electron‐ withdrawing substituents; 5) enclosing structural defects; 6) promoting supramolecular interactions between individual molecules governing their organization into a condensed phase, and 7) replacing selected carbon atoms by isostructural and isoelectronic analogues (i.e., doping).…”

Self-Assembly of Bodipy-Derived Extended π-Systems

“…Fundamental understanding of electronic ET 26,50,51 in lightharvesting biological systems are possible by mimicking them using properly designed synthetic materials. In this regard, supramolecular self-assembly is a viable choice because of its capacity to organize chromophores in a desired manner and thereby influence dynamics of exciton migration.…”

Nanophotonics and supramolecular chemistry

“…Ajayaghosh and coworkers have investigated the photonic characteristics of gel-type assemblies of rather small chromophore molecules [22][23][24]. For example, they researched thienylenevinylene-based gels ( Figure 1A) that exhibit epitaxial self-assembly to form aligned supramolecular wires [25].…”