Dual fluorescent zwitterionic organogels of a quinoxalinone derivative using cation–anion detection keys

Abstract

Both K+ and AcO ions became the key ions to lock the fluorescent organogel state of a crown-ether-fused quinoxalinone derivative.

Solid‐State Fluorescence of Excited‐State Cation–Anion Intermolecular Proton Transfer in 2‐(2‐Hydroxypyridyl)benzothiazole

“…[1][2][3][4][5] Most fluorescent sensing materials are utilized in aqueous solutions, while solid fluorescent materials can be keto (=O) conformation and a substantial change in the dipole moment between the ground and excited states, indicating a large Stokes shift near 10 000 cm −1 . [39][40][41][42][43][44][45] Chemically designing intramolecular hydrogen-bonding sites and the π-molecular framework enables multicolor fluorescence and high quantum yield to be obtained and has been applied to molecular sensing materials. A typical solid ESIPT fluorescent molecule has an intramolecular hydrogen-bonding site in the π-electron system wherein emission is unaffected by the molecular arrangement.…”

“…[ 29–38 ] Another simple π‐molecular system exhibiting a relatively high quantum yield has been developed in the intramolecular OH•••O and NH•••N hydrogen‐bonding molecular frameworks wherein excited‐state intramolecular proton transfer (ESIPT) exhibited considerable structural change from the enol (−OH) to the keto (=O) conformation and a substantial change in the dipole moment between the ground and excited states, indicating a large Stokes shift near 10 000 cm −1 . [ 39–45 ] Chemically designing intramolecular hydrogen‐bonding sites and the π‐molecular framework enables multicolor fluorescence and high quantum yield to be obtained and has been applied to molecular sensing materials. A typical solid ESIPT fluorescent molecule has an intramolecular hydrogen‐bonding site in the π‐electron system wherein emission is unaffected by the molecular arrangement.…”

ESIPT geometrical isomers with distinct mechanofluorochromism and intra/intermolecular H-bonding controlled tunable fluorescence

“…The structural change associated with the photochemical process of an ESIPT molecule leads to a substantial change in the dipole moment between the ground and excited states and causes a large Stokes shift. [19][20][21][22][23][24][25][26][27] The large Stokes shift significantly reduces self-absorption and enhances fluorescence efficiency. The structural design of intramolecular H-bonding sites and π-conjugated molecular structures enables one to achieve broad, tunable dual emissions that cover the whole visible spectrum, resulting in white light emission.…”

Tetranitro- and tetraamino-dibenzo[18]crown-6-ether derivatives: complexes for alkali metal ions, redox potentials, crystal structures, molecular sorption, and proton conducting behaviours

“…For instance, simple molecules of [15]crown-5 and [18]crown-6 exhibit high Na + and K + recognition abilities, respectively; here, the multiple electrostatic M + ⋯O interactions between M + and the lone pairs of oxygen atoms effectively fix the M + inside the cavity. [1][2][3]10 The selective M + recognition ability of crown ethers has been implemented for material designs with various physical properties, including absorptionfluorescence, [11][12][13] electrical conduction, [14][15][16] magnetic, [17][18][19][20] dielectric, 21,22 and ferroelectric responses. 23,24 The physical properties of π-conjugated molecules are dominated by the frontier orbitals of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) in the solution and solid phases, which can be controlled by the chemical design of the molecule.…”

“…For instance, simple molecules of [15]crown-5 and [18]crown-6 exhibit high Na + and K + recognition abilities, respectively; here, the multiple electrostatic M + ⋯O interactions between M + and the lone pairs of oxygen atoms effectively fix the M + inside the cavity. 1–3,10 The selective M + recognition ability of crown ethers has been implemented for material designs with various physical properties, including absorption–fluorescence, 11–13 electrical conduction, 14–16 magnetic, 17–20 dielectric, 21,22 and ferroelectric responses. 23,24…”