Solid-state emitters presenting a modular excited-state proton transfer (ESIPT) process: recent advances in dual-state emission and lasing applications

Abstract

This review aims at providing a broad readership of material and physical chemists, as well as those interested in ab initio calculations, about recent advances in the fields of dual...

Photoactive glycoconjugates with a very large Stokes shift: synthesis, photophysics, and copper(ii) and BSA sensing

“…The emission at longer wavelengths is associated with a very large Stokes shift (∼10 000 cm −1 ), as expected for ESIPT compounds. 55,56 Finally, for all compounds studied, excluding specific interactions present in a protic polar environment, no significant changes were observed at the maximum wavelengths upon increasing the solvent polarity.…”

Amplified spontaneous emission from a liquid crystalline phase: anisotropic property and active modulation

“…Although most ASE studies start from solution states shifting into solid or crystalline states of media, ASE from the liquid crystalline (LC) phase is less studied so far. 24,25 The liquid crystalline phase is especially advantageous to have a fast response to external stimuli such as electric fields and temperature due to its fluidity and oriented dipole moment. This controllable orientation of molecules in the LC phase is expected to allow the realization of dynamic manipulation of optical gain and ASE processes by using itself as a lasing media, which cannot be achieved in solution or crystalline states.…”

“…Various structural frameworks are reported to exhibit ESIPT with presenting ASE behaviour in solid or crystalline states. 24,28–32 Based on the representative ESIPT molecular motif of 2-(2-hydroxyphenyl)-benzothiazole (HBT), we designed a rod-like molecule with high aspect ratio: 2-(4-(1-hexynyl)-2-hydroxyphenyl)-benzothiazole (C4alkyne-HBT) showing relatively high fluorescence quantum yield in various media. 33 In this work, the detailed optical properties of C4alkyne-HBT in liquid crystalline media: 4-pentyl-4′-cyano biphenyl (5CB) have been studied as well as demonstrating anisotropic emission properties and dynamic control of the emission and optical gain.…”

Complexes on the Base of a Proton Transfer Capable Pyrimidine Derivative: How Protonation and Deprotonation Switch Emission Mechanisms

“…Kinetic barriers between the minima of the normal and tautomeric forms in the excited state can partially or fully suppress the proton transfer process and lead to the emission of the normal form. If the barriers separating the normal and tautomeric forms in the excited state are surmountable, ESIPT-capable compounds can show dual emissions associated with the fluorescence of both forms. − Along with singlet-to-singlet transitions, these molecules can be converted to the ground state through triplet excited states and triplet-to-singlet transitions such as phosphorescence (including room temperature phosphorescence) ,,− and thermally activated delayed fluorescence. − Some ESIPT-capable compounds exhibit anti-Kasha emissions, which can be observed in molecules wherein the first and the second excited states are separated by large energy gaps. − …”