Melt-induced fluorescent signature in a simple naphthalenediimide

Abstract

The synthesis and fluorescence properties of a naphthalenediimide ditosylate are presented. The fluorescence is highly solvent and morphology dependent with a dramatic change in fluorescence output occurring following melting from a crystalline form. This observation is attributed to thermal disruption of the crystal structure allowing the formation of emissive dimers within the amorphous melt.

Unraveling the Driving Forces in the Self-Assembly of Monodisperse Naphthalenediimide-Oligodimethylsiloxane Block Molecules

“…Hence, upon excitation (λ exc = 365 nm) 5 shows the typical blue-green luminescence (Figure 4c; Figures S115–S116) of NDIs observed in other bulk systems. 57 The same luminescence is observed on drop cast films of 5 : a broad, structureless emission band centered at 490 nm (blue-green) is visible in the fluorescence spectrum (Figure 4g). A very similar luminescence is observed with Si15-NDI-Si15 (Figure 4d and 4h; Figure S116) and Si15-NDI 2 -Si15 (Figure S115), suggesting somewhat similar interactions between NDI units in the columnar morphologies of family 1 , despite some clear differences in the UV–vis spectra (Figures S121–S123).…”

Harnessing Brightness in Naphthalene Diimides

“…The bis-tosylated NDI 7 (Figure 3g)s hows excimer emission in toluene( l em,max 525 nm). [16] Microcrystals of the material display only weak local singlet emission at l em,max % 430 nm, however heatingt oc reate am elt and subsequentc ooling,l eads to the formation of an amorphous material which exhibits ad ramatic increase in,a nd redshift of, the emission (l em,max % 500 nm) (Figure 10 e,f). The fluorescence emission is attributed to the formation of excimers, created throughd isruption of the offset-aromatic crystal packing ( Figure 3g).…”

“…The addition of long amphiphilic chainsi nto the imide positions, for example NDI 7,i sa lso capable of creating emissive nanoarchitectures( Figure 3g). [16] The enhancement of fluorescence emission through aggregate or solid state structures is a phenomenon known as aggregation-induced emission (AIE). [10] In non-core-substituted NDI examples, this technique has been used to induce excimer emission, where co-facial stacking between NDI units produces an excited dimer state, although most literature examples do not clearlyi dentify whether dimers or highera ggregates are formed.…”

“…[36] Such emissive soft matter materials have been highlighted for potential in drug delivery systems andb iosensing applications.S imilar organogels are also observed using simple l-alanine and l-phenylalanine-substituted NDIs to form blue/green to cyan-emitting soft materials, [37] attributed to the formationo fs olid-state excimers and other p-stack systems. [16].Copyright 2010 The Royal SocietyofC hemistry.g )Molecular structure of NDI-triazole cyclophane 37 and h) the mechanism of Mg 2 + sensing in NDI-triazole cyclophane 37.Reproduced with permission from Ref. [38].Copyright 2012W iley-VCH.…”

An Aza‐12‐crown‐4 Ether‐Substituted Naphthalene Diimide Chemosensor for the Detection of Lithium Ion

“…Among small aromatic molecules, core‐substituted naphthalene diimides (cNDIs) have attracted attention due to their capability for producing an optical readout, color monitoring and redox behaviour during sensing of ions . cNDIs also have been used for various applications such as supramolecular self‐assembly, solide‐state emitter, sensing of anion and cation, artificial photosynthesis, pH sensing, solar cells, medical science and biology …”