Solventless synthesis of a Schiff base that forms highly fluorescent organic nanoparticles exhibiting aggregation-induced emission in aqueous media

Figures & data

Figure 1 . Synthetic route for preparation of DBD. Two drops of acetic acid are used to catalyse the reaction.

Figure 2. Suggested fragmentation of DBD.

Figure 3. Atomic force microscope (AFM) images of (a) DBD nanoparticles in H₂O CTAB, with diameters around 55 nm (b) DBD in H₂O with diameters around 75 nm (c) DBD in H₂O triton, with diameters around 90 nm.

Figure 4. (a) Photograph showing DBD in solution (dissolved in THF) and DBD as nanoparticles (in aqueous solution). (b) Normalised absorption spectra of DBD in THF solution and as nanoparticles with and without surfactants. (c) Normalised photoluminescence spectra. DBD in THF gives almost no emission. (d) Comparing emission spectra of DBD/H₂O in HAC to DBD/H₂O triton.

Figure 5. Photographs of DBD spot in the absence of chloroform vapour (left) and after exposure to chloroform vapour for one hour (middle) and three hours (right). The spot was illuminated under UV 365 nm light.

Table 1. Photophysical behaviour of DBD in solution and DBD nanoparticles.

	Absorption λmax (nm)	Emission λmax (nm)	Stokes shift
DBD in THF	384	–
DBD/H2O NPs	370	495 (sh)*, 525	155
DBD/H2O–CTAB	400	495 (sh), 525	125
DBD/H2O–triton	347	400	53

*Sh: shoulder.