Blue‐Light‐Emitting Triazolopyridinium and Triazoloquinolinium Salts

Abstract

Compounds that emit blue light are of interest for applications that include optoelectronic devices and chemo/biosensing and imaging. The design and synthesis of small organic molecules that can act as high‐efficiency deep‐blue‐light emitters in the solid state and can be easily processed from solutions represents a significant challenge. Herein we present the preparation and photophysical, photochemical and electrochemical properties of a series of triazolopyridinium and triazoloquinolinium compounds. The compounds are soluble in water or polar organic solvents and exhibit photoluminescence in the blue region of the spectrum in fluid solution, in the solid state and in a frozen matrix.

Supramolecular arrangement and photophysical properties of a dinuclear cyanophenylboronic acid ester

“…diagram, this emission corresponds to the blue region with X = 0.1667 and Y = 0.2102 (Carboni et al, 2017).…”

Beyond “Mega”: Origin of the “Giga” Stokes Shift for Triazolopyridiniums

“…Compared to “mega” Stokes shift fluorophores, , a much smaller set of molecules have Stokes shifts greater than 10,000 cm –1 , − for whom we suggest the designation “giga” Stokes shift. In the past, “mega” Stokes shift fluorophores have been utilized for imaging, ,− thermometry, , sensing, − and organic light-emitting diode (OLED) applications.…”

“… TOP exhibited a “giga” Stokes shift of 11,790 cm –1 in water, and the excitation transition was assigned to intramolecular charge transfer based upon TDDFT calculations. Later, in 2017, efficient syntheses of the triazoloquinolinium monomer (TOQ) and triazoloquinolinium dimer (TOQ 2 ) were reported, along with more extensive characterization of the photophysics for this family of dyes . Importantly, X-ray crystallographic characterization of TOP, and computational modeling of TOQ, has indicated that these molecules adopt twisted ground-state geometries.…”

“…Next, the excitation spectra for all four dyes were modeled by TDDFT calculations using the same six functionals. The accuracies of these predictions were gauged by comparing the experimental and TDDFT-predicted UV/Vis absorption (Abs) spectra. , Finally, TDDFT was employed to predict the excited-state (S 1 ) geometries and emission spectra for TOP, TOP 2 , TOQ, and TOQ 2 . The experimental and predicted Stokes shifts were compared to judge the accuracy of these calculations.…”

Metal‐ and Photoredox‐Catalyst Free Unified Approach for the Synthesis of Azole‐Fused Quinolines via tert‐Butyl Nitrite‐Mediated Regioselective Annulation

“…[7] The 1,2,3‐triazolo[1,5‐ a ] quinoline is not only the core unit of Diquat, a DNA interacting agent, and AZ1, an aryl hydrocarbon receptor (AhR) agonist but forms part of many other bioactive agents [8] . In addition, compounds with this scaffold are disclosed to be blue light emitters for neon LED [9] and serve as starting material for the synthesis of a variety of quinoline derivatives [10] . The pyrrolo[1,2‐ a ]quinoline system is a subunit of the natural product Lamellarin and other pharmacologically active compounds, which show activities such as apoptosis inhibitor, antibacterial, antiproliferative and others [11] .…”