A novel 2,6-bis(benzoxazolyl)phenol macrocyclic chemosensor with enhanced fluorophore properties by photoinduced intramolecular proton transfer

Abstract

The macrocyclic ligand L, in which a triethylentetramine incorporates a 2,6-bis(2-benzoxazolyl)phenol (bis-HBO) group, was designed and synthesized with the aim to create a chemosensor with high selectivity and specificity for...

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

“…The emission of ESIPT-capable dyes is highly sensitive to solvents, 43–50 substitution in the ESIPT-dye core, 51–71 protonation/deprotonation, 72–80 and coordination of metal ions. 81–96 Normally, the latter process is coupled with the deprotonation of ESIPT-dyes. 81–96 However, the rational design of ESIPT-capable molecules featuring spatially separated sites for accommodating both a metal ion and the mobile H + ion, i.e.…”

“…81–96 Normally, the latter process is coupled with the deprotonation of ESIPT-dyes. 81–96 However, the rational design of ESIPT-capable molecules featuring spatially separated sites for accommodating both a metal ion and the mobile H + ion, i.e. , the metal binding site and the ESIPT site, paves the way toward the coordination of metal ions without the deprotonation of the ESIPT-dyes.…”

“…42 The emission of ESIPT-capable dyes is highly sensitive to solvents, [43][44][45][46][47][48][49][50] substitution in the ESIPT-dye core, protonation/deprotonation, [72][73][74][75][76][77][78][79][80] and coordination of metal ions. [81][82][83][84][85][86][87][88][89][90][91][92][93][94][95][96] Normally, the latter process is coupled with the deprotonation of ESIPT-dyes. [81][82][83][84][85][86][87][88][89][90][91][92][93][94][95][96] However, the rational design of ESIPTcapable molecules featuring spati...…”

“…[81][82][83][84][85][86][87][88][89][90][91][92][93][94][95][96] Normally, the latter process is coupled with the deprotonation of ESIPT-dyes. [81][82][83][84][85][86][87][88][89][90][91][92][93][94][95][96] However, the rational design of ESIPTcapable molecules featuring spatially separated sites for accommodating both a metal ion and the mobile H + ion, i.e., the metal binding site and the ESIPT site, paves the way toward the coordination of metal ions without the deprotonation of the ESIPT-dyes. This strategy allows one to synthesize ESIPT-capable coordination polymers and molecular ESIPT-capable metal complexes, [118][119][120][121][122][123][124] which are extraordinarily rare classes of ESIPT-capable materials at the moment.…”

Efficient emission of Zn(ii) and Cd(ii) complexes with nopinane-annelated 4,5-diazafluorene and 4,5-diazafluoren-9-one ligands: how slight structural modification alters fluorescence mechanism

“…Zinc( ii ) and cadmium( ii ) complexes establish one of the most important classes of emissive compounds. 71–121 Earlier, we synthesized a series of mononuclear zinc( ii ) and cadmium( ii ) complexes with hybrid ligands containing a 2,2′-bipyridine moiety and natural terpene (+)-limonene or (+)-3-carene moieties and demonstrated that they exhibit luminescence with the quantum yield increasing in the following order: free ligand < cadmium( ii ) complex < zinc( ii ) complex. 122 The complexes with the limonene derivative demonstrate excitation wavelength–dependent emission with nanosecond and microsecond lifetimes of the excited states.…”