Configuration-dependent optical properties and acid susceptibility of azulene compounds

Abstract

Configuration-dependent optical and sensing properties of azulene compounds were achieved simply by changing the conjugation direction, either along or orthogonal to the dipole direction of azulene. Their application as chemical sensor with sensitivity at ppm level was also demonstrated.

Synthesis and Halochromic Properties of 1,2,6‐Tri‐ and 1,2,3,6‐Tetra‐aryl Azulenes

“…Diethyl 2‐aminoazulene‐1,3‐dicarboxylate ( 1) was prepared according to the reported method [55] . Compound 6 was prepared starting from compound 1 with approximately 10 % yield according to the literature methods, [54] and their spectroscopic data were summarized in the supporting information. Then, compound 6 was brominated with an optimal amount of NBS to generate brominated products, which were composed of a mixture of mono‐brominated, di‐brominated and tri‐brominated 6 .…”

Azulenes with aryl substituents bearing pentafluorosulfanyl groups: synthesis, spectroscopic and halochromic properties

“…There are precedents for this phenomenon. Wang, He and co-workers have studied azulenes bearing thienyl substituents; 23 Hawker and co-workers have studied azulenes bearing diketopyrrolopyrrole substituents; 24 and Murai, Takai and co-workers have studied analogues of 6 and 8 with a -CF 3 group in the place of the -SF 5 group. 25 In each case a more significant change in absorption maxima (and hence colour) is observed for the isomer with the substituent(s) aligned with (instead of orthogonal to) the dipole of the azulene core, i.e.…”

BN Fused Diazulenyl‐Carbazole: Synthesis, Structure, and Properties

“…[ 26 ] Therefore, azulene and its derivatives have been considered as promising candidates for sensors. [ 27‐28 ] By combining boron‐nitrogen pair with azulene, we envision that the two motifs could work in a synergistic way to develop molecular sensors with better performance.…”