<i>N</i>‐2‐Aryl‐1,2,3‐triazoles: A Novel Class of UV/Blue‐Light‐Emitting Fluorophores with Tunable Optical Properties

Abstract

Abstract 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.