Structural isomerism induces pH dependent AIE-coupled ESIPT: an in-depth spectroscopic exploration with application in amine vapor sensing

Abstract

A novel excited state intramoelcular proton transfer probe 3-(benzo[d]thiazol-2-yl)-4-hydroxy-5-methoxybenzaldehyde (3BTHMB) was synthesized and characterized by NMR, ESIMS and single crystal diffraction studies. The steady state and time resolved studies using...

Interrogating the nature of aggregates formed in a model azine based ESIPT coupled AIE active probe: stark differences in photodynamics in the solid state and aggregates in water

“…The assignment assumed that AIEgens behave in aqueous aggregates in a similar way to their behaviour in solid-state. 8 In contrast to the solid state observations, the contribution of the H-aggregates is considerably greater than the J-aggregates in water and at 600 nm, i.e. the tail end of the emission spectrum, the contribution of both forms is roughly similar.…”

“…However, the behaviour of BNHMP in organic solvents could be understood very well and a photophysical scheme was drafted to elucidate the various photoprocesses operative in the title compound (Scheme 2) in accordance with existing reports. 6,8,14,44…”

“…Considering the J-aggregates show longer emission lifetimes, τ 1 and the τ 2 components were assigned to be from the H- and J-aggregates respectively based on previous reports. 8,57…”

“…The research on aggregation induced emission (AIE) active chromophores has found a new impetus since the observation of coupling of excited state intramolecular proton transfer (ESIPT) to the AIE process. 7–13 The aforementioned impetus is principally because of the multifarious ways this coupling is utilized in terms of sensing, 8,10 bioimaging as well as energy harvesting processes. 9,12,13…”

Water‐Assisted Photoinduced Tautomerization in a Potential Bioactive Semicarbazone Schiff Base

“…À 1 : 3431 (NH 2 ), 3334-2775 (OH), 1677 (C=O), 1636 (C=N), 1 H NMR (400 MHz, CDCl 3 ) δ (ppm): 1.19 (t, 6H, (N-CH 2 -CH 3 ) 2 ), 2.17 (s, 1H, -CH), 3.39 (q, 4H, (N-CH 2 -CH 3 ) 2 ), 6.21 (s, 2H, NH 2 ), 6.25 (d, 1H, ArÀ H), 7.0 (d, 1H, ArÀ H), 7.31 (s, 1H, ArÀ H), 7.7 (s, 1H, NH), 7.9 (s, 1H, OH) 13. C NMR (400 MHz, DMSO) δ (ppm): 157.7 (C-OH), 156.4 (C=O), 149.3 (CH=N), 140-97 (aromatic -CÀ ), 43.7 (N-CH 2 -CH 3 ), 12.5 (N-CH 2 -CH 3 ).…”