Dual-state emission and photochromic properties of spiropyranindoline derivatives bearing an ortho-hydroxyphenylbenzimidazole moiety

Luminescence of ESIPT-capable zinc(ii) complexes with a 1-hydroxy-1H-imidazole-based ligand: exploring the impact of substitution in the proton-donating moiety

“…However, if kinetic barriers are high enough to impede the ESIPT photoreaction, the N-form of the molecule can emit itself and can produce dual emission associated with the emission of both forms of the molecule. [21][22][23][24][25][26][27][28][29][30][31] Furthermore, the emission of ESIPT-dyes often involves triplet excited states, giving rise to phosphorescence (including room temperature phosphorescence) and thermally-activated delayed fluorescence. [32][33][34][35][36][37][38][39][40][41] This plethora of emissive excited states makes ESIPT-capable compounds an appealing platform for the design of multicolor luminescent materials.…”

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. − …”

A Cu 2+ triggered reversible photochromic system: the structure photochromic response relationship study and potential applications

“…Therefore, salicylaldehyde or 2-pyridine carboxaldehyde derivatives which have an ortho-coordination site were employed for coupling with rhodamine B hydrazide to construct photochromic system in most of the follow-up studies [19][20][21][22][23][24][25][26]. Although great progress has been made in the development of photochromic materials [27][28][29], the structure photochromic response relationship (SPRR) of RhBHH-based photochromic materials are still blurry. In addition, due to the strong chelation of the above RhBHH derivatives, no photochromic phenomenon would be observed or too much bleaching time would be needed when Cu 2+ was used as the trigger [18].…”