Harnessing Brightness in Naphthalene Diimides

Abstract

The development of brightly emissive compounds is of great research and commercial interest, with established and emerging applications across chemistry, biology, physics, medicine and engineering. Among the many types of molecules available, naphthalene diimides have been widely used for both fundamental photophysical studies and in practical applications that utilise fluorescence as an information readout. The monomeric naphthalene diimide is weakly fluorescent, however through various methods of core‐derivatisation, it can be developed to be highly fluorescent and further functionalised to add utility. In this review, we highlight recent advances made in naphthalene diimide chemistry that have led to development of molecules with improved optical properties, and the design strategies utilised to produce bright fluorescence emission as small molecules or in supramolecular architectures.

Base‐Assisted Imidization: A Synthetic Method for the Introduction of Bulky Imide Substituents to Control Packing and Optical Properties of Naphthalene and Perylene Imides

“…The UV/Vis absorption and fluorescence emission spectra of the imides 6 – 9 in chloroform solution show the characteristic vibronic patterns of the monomeric dyes (Figures S10–13, Tables S11–14) . While perylene imides 8 and 9 are highly fluorescent with quantum yields close to unity, naphthalene imides 6 and 7 show negligible fluorescence in solution ( Φ fl <0.5 %), which is due to deactivation through close triplet states …”

“…[4,6] While perylene imides 8 and 9 are highly fluorescent with quantum yields close to unity, naphthalene imides 6 and 7 show negligible fluorescence in solution (F fl < 0.5 %), which is due to deactivation through close triplet states. [28,29] Pronounced effects of the bulky N-substituents were observed in the solid-state optical properties.T he absorption spectra of spin-coated thin-films of the imides largely resemble their respective solution spectra (Figures S14 and S15, Table S15). Thevibronic structure becomes sharper with increased bulkiness of the substituents.T his suggests am ore effective shielding of the rylene cores and less intermolecular couplings.…”

Long-lived triplet charge-separated state in naphthalenediimide based donor–acceptor systems

“…Due to their high stability, good solubility and ease of functionalization, 1,4,5,8-naphthalenediimides (NDIs) are among the most used molecular building blocks in supramolecular chemistry. [1][2][3][4][5][6][7] Their high oxidative power and the good stability of their radical anions make NDIs popular electron accepting units in multichromophoric systems. [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] In principle, they can also act as chromophores due to their strong p-p* transition around 375 nm.…”

Naphthalene diimide–amino acid conjugates as novel fluorimetric and CD probes for differentiation between ds-DNA and ds-RNA

“…These inspiring results encouraged us to broaden the palette of available amino acid (AA)-chromophore conjugates. Therefore, in this work we have chosen a naphthalene diimide (NDI) chromophore [17][18][19][20], a well-known DNA/RNA binding moiety, which differs from previously used dyes by its ability to intercalate into ds-DNA/RNA by "threading" through the polynucleotide double helix [21,22]. Such "threading intercalation" indicates that a large aromatic moiety with bulky groups at opposite ends is inserted between two DNA or RNA base pairs, whereby bulky substituents end in both, the minor and major groove of the polynucleotide.…”