Excitation wavelength-dependent room-temperature phosphorescence: unusual properties of novel phosphinoamines

Abstract

Exploring pure organic single-component materials featuring room-temperature phosphorescence and excitation-dependent color-tunability attracts great attention in recent years. Such challenging materials are highly demanded for the OLED industry and are very...

Tuning ESIPT-coupled luminescence by expanding π-conjugation of a proton acceptor moiety in ESIPT-capable zinc(ii) complexes with 1-hydroxy-1H-imidazole-based ligands

“…8–10 The excitation of such a molecule in its normal form ( N ) with light results in the transfer of the electron density from the electron-donating group to the electron-accepting one, which in turn alters the acidity and basicity of the proton-donating and proton-accepting groups and promotes the proton to transfer (excited state intramolecular proton transfer, ESIPT) affording the tautomeric form ( T ) of the molecule (Scheme 1). 11–32 If the ESIPT process is barrierless, the only form to emit is the tautomeric form. This emission is associated with dramatic reorganization of the molecular structure, resulting in large Stokes shifts.…”

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…”

“…Excited state intramolecular proton transfer (ESIPT) is one of the simplest photochemical reactions. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] This reaction is the second part of a four-level photochemical process which includes (i) the excitation of an ESIPT-fluorophore in its normal form, (ii) an excited state tautomerization (the ESIPT process itself), (iii) the emission in the tautomeric form and (iv) a ground state intramolecular proton transfer (GSIPT) (Scheme 1). 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.…”

“…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][2][3][4][5][6][7][8][9][10][11][12][13][14][15] The ESIPT reaction is sensitive to the nature of the hydrogen bond donor and acceptor groups as well as to the hydrogen bond length. [16][17][18] Most ESIPT-fluorophores make use of the O-H⋯N intramolecular hydrogen bond pattern with a hydroxyphenyl group as a hydrogen bond donor and an imino/ heteroaromatic N atom as a hydrogen bond acceptor.…”

Metal‐Free Organic Triplet Emitters with On–Off Switchable Excited State Intramolecular Proton Transfer

“…As TADF and RTP materials received wide attention in the past decade, recently, the intrinsic intramolecular charge transfer of ESIPT structures has been utilized to activate TADF in organic light-emitting devices, [16][17][18] followed by a few photophysical and computational study of their excited state dynamics. [19][20][21] On the other hand, however, activating RTP from ESIPT molecules is much less explored [22,23] while most photophysical studies focus on low-temperature phosphorescence properties. [24,25] Moreover, as these pioneering works explored the keto-form properties of ESIPT triplet emitters, molecular engineering pathways to harvest triplet energy from the enol tautomer is missing.…”