Tunable emission in aggregated T-Shaped 2H-Benzo[d][1,2,3]triazoles with waveguide behaviour

Abstract

Symmetrical Donor-Acceptor-Donor (D-A-D) 2H-benzo[d][1,2,3]triazole derivatives have been designed by DFT calculations and prepared by a multistep synthetic protocol. The design strategy involved the identification of a suitable acceptor benzotriazole core and modification of the steric volume and donor strength of the branches in order to modulate the Intramolecular Charge Transfer (ICT) process and, consequently, the band gap. Self-assembly of the reported triazoles afforded organized supramolecular structures, the morphologies of which were visualized by SEM imaging. The outcomes demonstrated the effect that the donor moiety has on the emission properties and the morphologies of the aggregates. The aggregates that had a crystal-like structure, with smooth surfaces and flat end facets, exhibited optical waveguide behaviour with tunable colour emission. Depending on the initial design, the different emission wavelengths are related to the band gap of the benzotriazole derivatives.Keywords Tunable colour emission Waveguide Self-Assembly T-shaped 2H-benzo[d][1,2,3]triazole at the donor-acceptor heterojunction. The frontier molecular orbital profiles are shown in Figure 1.

Extended Alkenyl and Alkynyl Benzotriazoles with Enhanced Two‐Photon Absorption Properties as a Promising Alternative to Benzothiadiazoles

“…[h] OP absorption and emissions obtained from ref. . [i] OP absorption and emissions obtained from ref.…”

“…Thus, we have described alkynyl‐BTz derivatives ( 1 ) (Figure ) with a wide variety of applications, as indicated above. These compounds were synthesized by means of a Sonogashira C−C cross‐coupling reaction under microwave (MW) irradiation …”

“…Nevertheless, the NTO electrons are fully centered along the core of the molecules. This pronounced change in electron density was previously related to an ICT process; this agrees with the experimental data for these dyes . Going further, the S 1 ←S 0 transition is mainly populated by the HOMO and the LUMO frontier orbitals.…”

“…In addition to BTDs, our research in recent years has also focused on 2 H ‐benzo[ d ][1,2,3]triazole (BTz) as another benzoazole derivative. BTz is an interesting option to consider due to its excellent photophysical properties . Despite the fact that BTz has a less accepting core than that of BTD, this unit allows better functionality.…”

“…BTz and its derivatives are known to be multitasking units with applications in different fields, such as antifreeze and corrosion‐inhibiting agents, or as copolymers in donor–acceptor (D‐A) polymers for solar cells . In recent years, our research group has also described their applications as optical waveguides, semiconductors in organic field‐effect transistors (OFETs), organogels, and bioimaging …”