Emission color-tunable oxazol(in)yl-substituted excited-state intramolecular proton transfer (ESIPT)-based luminophores

Abstract

Oxazolinyl- and arylchalcogenazolyl-substituted hydroxyfluorenes exhibiting excited-state intramolecular proton transfer (ESIPT) are described as potent and highly modular luminophores.

New 3,1,2,4-benzothiaselenadiazines, related π-heterocycles including Herz cations, radicals and molecular complexes, and Bunte salts

“…Using 77 Se NMR, intermediate compound 29 was detected under conditions of SbPh 3 -catalyzed hydrolysis in CDCl 3 (Scheme 9); for 29 , δ 77 Se = 913 ppm is similar to that of related Ar–Se–NSN–R (R = SiMe 3 , Se–Ar) and different from δ 77 Se = 405 ppm of 2,2′-diaminodiphenyl diselenide. 23 The hydrolysis of dithiadiazine 30 in wet Et 2 O proceeds quickly only at 100 molar% of the NH 3 catalyst to give the Bunte salt 31 ; with 25 molar% of NH 3 , a slower reaction allows the detection of the intermediate N -sulfinyl 32 together with starting 30 and disulfide 33 . 3 b ,24 These results indicate the enhanced hydrolytic stability of 30 and 32 under moderate basic conditions (Scheme 9).…”

Substitution Effect on 2-(Oxazolinyl)-phenols: Emission Color-Tunable, Minimalistic Excited-State Intramolecular Proton Transfer (ESIPT)-based Luminophores

“…16 Very recently, we investigated oxazolinyl-and arylchalcogenazolyl-substituted hydroxyfluorenes as emission color-tunable luminophores. 17 Reasoned by these findings we implemented the oxazoline group as a highly efficient proton acceptor in ESIPT-based luminophores and extended their usage as a protecting and directed metalation group (DMG). 18 Moreover, not only the oxazoline group, but the entire 2-(oxazolinyl)-phenol motif is found in several natural products like spoxazomicins and tetroazolemycins, making the study of such structural motifs of greater importance.…”

N-Hydroxy–N-oxide photoinduced tautomerization and excitation wavelength dependent luminescence of ESIPT-capable zinc(ii) complexes with a rationally designed 1-hydroxy-2,4-di(pyridin-2-yl)-1H-imidazole ESIPT-ligand

“…As a result of the excited state tautomerization, the ESIPT-fluorophores tend to exhibit large Stokes shifts which reduce the inner filter effect and are not achievable for most conventional fluorophores. 1–15…”