Formation of a supramolecular chromophore: a spectroscopic and theoretical study

Abstract

Spectroscopic and theoretical investigations of the self-assembly of a particular 1,3,5-benzene trisamide-based low molecular weight hydrogelator are described. This trisamide is pH-sensitive, and surprisingly forms a photoluminescent supramolecular hydrogel. Controlled gel formation in combination with the luminescence properties allows studying the self-assembly process in detail. The experimental results are confirmed by Density Functional Theory (DFT) calculations, revealing that the photoluminescence originates from the formation of a supramolecular chromophore.

Influence of side-chain interactions on the self-assembly of discotic tricarboxyamides: a crystallographic insight

“…The synthesized compounds were puried and characterized by 1 H-NMR, 13 C-NMR, FT-IR and mass spectrometry (MS) analysis. In this context the folding and interactions of hydrophobic groups will be interesting.…”

“…4 But the role of side-chain interactions in the peptide mimetic is largely unexplored. 11 Versatile tricarboxyamide derivatives have been synthesized by incorporating diverse functional groups such as alkyl, 12 aryl, 13 pyridyl, 14 bipyridyl, 15 porphyrinyl, 16 triphenylyl, 17 oligo(p-phenylenevinylene), 18 amino acid, 19 dipeptide, 20 oligopeptide, 21 oligo-(ethyleneoxy), 22 and benzocrown ethers. 8 Moreover, the building blocks need a delicate balance of the intramolecular and intermolecular non-covalent interactions.…”

Influence of Metal, Ligand and Solvent on Supramolecular Polymerizations with Transition‐Metal Compounds: A Theoretical Study

“…Only for light atoms is the electronic contribution to the partition function negligible because of the very large energy difference between ground and first excited state. 36 For much heavier systems, where excited states or energy levels can become very close to each other, 19,35 the electronic partition function becomes increasingly more important, i.e., the degree of accessibility of the electronic states of the system becomes higher. For aggregates of 1 and 2, which exhibit considerably smaller HOMO-LUMO gaps and metal-metal distances (see Figs.…”

“…For 1-3, the singlet and triplet excited states are expected to red shift upon increasing the aggregate length, and this has been in fact observed for metal-free supramolecular columns composed of benzene-and cyclohexane-trisamides. 19,35 The aggregates of 1-3 behave like J-aggregates, as these compounds always show excited states bathochromically shifted with respect to the monomer state. Since the HOMO-LUMO gap is inversely proportional to the polarizability, 19 the trends shown in Fig.…”

“…2b), or even by the red shift of excited states exhibited by other 1D aggregates. 35 The higher electron delocalization and polarizability lend a higher mobility to the electrons. It becomes then clear that the electronic part of the system, instead of getting more organized and localized, is becoming more disorganized upon self-assembling and therefore ΔfS would tend to be more positive.…”