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

Abstract

A novel ESIPT active Schiff base BNHMP showed AIE by equal extent of formation of H and J aggregates in water, as opposed to predominant J aggregates in solid state as evidenced from spectroscopic studies.

Dual-Channel Imine-Amine Photoisomerization in a Benzoimidazole and Benzothiazole Coupled System: Photophysics and Applications

“…The slower lifetime component (∼7.0 ns) was assigned to the lifetime of the local emission of the imine form and the two other components were assigned to the two amine forms. ,,, The contribution of the two amine forms increases as we move toward the low energy ESIPT emission bands. When the assigned anionic emission band was monitored, a faster lifetime component of 0.49 ns was obtained. − Thus, the faster lifetime value of BIBTB in DMSO, ACN, and MeOH solutions was assigned to the anion. Among the two amine forms, one is formed due to ESIPT toward the imidazole moiety and the other due to ESIPT toward the thiazole moiety.…”

“…For investigating the mechanism of PA detection, we have presented the relative energies of the frontier molecular orbitals of both BIBTB and PA, which demonstrate a favorable energy level alignment for the electron transfer from the photoexcited BIBTB to PA. − , …”

“…This was further confirmed by comparing the lifetime values in different solvents at different wavelengths (Table 4 and Figures S19−S21). 56 In the case of nonpolar solvents like CHCl 3 , as we move toward the ESIPT band at 555 nm, initially the contribution of the faster lifetime component increases from 430 to 510 nm and reaches a maximum at 510 nm, and is around 93%. Then, on moving from 540 to 600 nm the contribution of the slower lifetime component increases and that of the faster component decreases.…”

“…The slower lifetime component (∼7.0 ns) was assigned to the lifetime of the local emission of the imine form and the two other components were assigned to the two amine forms. 26,31,55,56 The contribution of the two amine forms increases as we move toward the low energy ESIPT emission bands. When the assigned anionic emission band was monitored, a faster lifetime component of 0.49 ns was obtained.…”

Investigating the Photophysical Aspects of a Naphthalene-Based Excited-State Proton Transfer Dye 1-(1H-Benzo[d]imidazol-2-yl)naphthalen-2-ol: pH-Dependent Modulation of Photodynamics

“…After disentangling the photophysical events in the solution phase, the time-resolved spectral behavior in the solid state was targeted since very interesting aggregate-dictated emission behavior is reported to occur in the solid-state photodynamics of ESIPT-based emitters. ,− Figure shows the time-resolved emission decay profiles of H-BINO in the solid state, and Table depicts the values of the lifetime components in the solid state.…”