Slow diffusion co-assembly as an efficient tool to tune colour emission in alkynyl benzoazoles

Abstract

We report here the preparation of co-assembled microcrystals by employing an easy, reproducible and cost-effective technique, namely slow diffusion. 2,3]triazole and benzo [c][1,2,5]thiadiazole were chosen as host and guest skeletons, respectively. Structural similarities allowed the correct co-assembly of the two structures. The co-assemblies were studied by different techniques that included Raman spectroscopy and X-ray diffraction, amongst others. The waveguiding properties and the emission colour of the doped organic microcrystals were also investigated. It was found that changes in the molar ratio of the different doping agents could tune the light emission. Fluorescence microscopy images of the co-assembled microcrystals revealed light colour changes from green to whitish, up to CIE coordinates of (0.370, 0.385). These tunable colour-active materials could be useful in the fields of optoelectronics or lab-on-a-chip for integrated optical circuits at micro-/nanoscale.

New insights into structure/optical waveguide behavior relationships in linear bisethynylbenzenes

“…Thus, encouraged by the need to deepen the knowledge of the relationship between the crystal structure and waveguide properties and based on our previous experience in this field, 42–49 this paper reports the synthesis, aggregate formation and study of the crystal structure and waveguide properties of a series of 1,4-bis(phenylethynyl)benzene derivatives (Fig. 1).…”

“…For this purpose, methoxy and CF 3 groups have been introduced at different positions of the carbon backbone, since in previous studies by our research group they have shown a great ability to form supramolecular aggregates. 43–46,49…”

Optical Waveguides in Organic Crystals of Polycyclic Arenes

“…Recently, a series of coassembled microcrystals with 2H-benzo [d][1,2,3]triazole (1) as host and benzo [c][1,2,5]thiadiazole derivatives (2a, 2b, 2c) as guest were reported by Prieto et al (Figure 25A). [39] In this way, Förster' resonance energy transfer occurred between the two components, leading to optical properties strikingly different from the individual crystals, and tunable by varying the doping ratio. The cocrystals of 1 and 2a propagated green and greenred light with doping ratios of 1:0.1 and 1:0.3, respectively.…”