Study on the Fluorescent Activity of N²-Indolyl-1,2,3-triazole

A new type of blue emitter, N²-Indolyl-1,2,3-triazoles (NITs), with the λ_max ranging from 420–480 nm and the Stokes shift from 89–143 nm, were synthesized through the coupling reaction of indoles with triazole derivatives. The influence of different substitution patterns on the optical properties (efficiency, excitation, and emission wavelengths) of the NITs was investigated. In addition, one palladium complex were synthesized by using NITs as the ligands, which, however, exhibited no fluorescent activity, but did show the enhanced co-planarity. Lastly, two bio-active molecule derivatives were explored for the potential use of these novel dyes in related chemical and biological applications.

Synthesis and characterization of bis-N-2-aryl triazole as a fluorophore

Naphthalene-bridged bis-triazole (NBT) complexes were prepared and characterized for investigation of their photophysical properties. Unlike our previously reported N-2-aryl triazoles, which gave strong emissions through the planar intramolecular charge transfer mechanism (coplanar conformation), this newly developed NBT adopted a noncoplanar conformation between triazole and naphthalene, achieving fluorescence through twisted intramolecular charge transfer.

Unexpected and powerful effect of chlorobenzene in direct palladium-catalyzed cascade Sonogashira–hydroarylation reaction

A ubiquitous accelerating effect of chlorobenzene (PhCl) was observed unexpectedly in the Pd-catalyzed cascade Sonogashira–hydroarylation reaction.

N-2-aryl-1,2,3-triazoles: a novel class of UV/blue-light-emitting fluorophores with tunable optical properties

The N-2-aryl-1,2,3-triazole derivatives (NATs) were developed as a new class of UV/blue-light-emitting fluorophores. Though both N-1-aryl-1,2,3-triazoles and N-2-aryl-1,2,3-triazoles gave strong photo absorption under excitation at 330 nm, only the N-2-analogous showed strong fluorescence emission in the UV/blue range with high efficiency in various solvents (quantum yield Φ around 0.3-0.5). Significant substituted group effects were observed, allowing tunable optical properties with emission (λ(max)) from 350-400 nm and Stokes shift from 38-93 nm. The computational studies along with X-ray crystal structures indicated the significance of the effective conjugation between triazole ring and aryl groups on the N-2 position. The planar intramolecular charge transfer (PICT) mechanism was proposed, which was supported by solvent effect studies. Simple derivatizations gave NAT-modified lysine and strong UV/blue emitting bis-NAT (Φ=0.76, λ(max)=390), which suggested the great potential of this new class of fluorophores in biological and material science research.