Evaluation of metal ion sensing behaviour of fluorescent probe along with its precursors: PET-CHEF mechanism, molecular logic gate behaviour and DFT studies

Asymmetric Schiff base ligand enables synthesis of fluorescent and near-IR emitting lanthanide compounds

“…In the emission spectra of the Gd 3+ and Yb 3+ complexes, the fluorescence enhancement is more than the other Ln-complexes. This has been reported earlier for complexes with suitable metal ion and fluorescent ligands which is referred to as the chelation-enhanced fluorescence effect (CHEF) and leads to 'turn-on' fluorescence [38][39][40][41]. Intermolecular energy transfer between the fluorescent ligands and lanthanide ions is one of the most significant processes, which can influence the fluorescent properties.…”

Analyses on intracellular Fe3+ with a rhodamine probe: “turn-on” response, specific recognition and bioimaging

“…In the DFT model, analyses on the combination of J3 –Fe 3+ found that N 2 and O 1 around the spirolactam ring were the most probable recognition sites to capture Fe 3+ (ref. 28 and 29) (Fig. 10).…”

Evaluation of Fluorescent Cu2+ Probes: Instant Sensing, Cell Permeable Recognition and Quantitative Detection

“…In J6/J7, the two oxygen and one nitrogen atoms located around the spirolactam ring, with higher nucleophilic activity towards Cu 2+ , probably act as the recognition sites to capture target Cu 2+ . When the spirolactam ring opens and thus the three atoms form an appropriate cavity to hold Cu 2+ , then the unbonding electron pairs of the two oxygen and one nitrogen atoms will partly be provided to fulfill the empty electron orbits of Cu 2+ through intramolecular forces [ 27 , 28 ], though weaker than coordination bonds, an obvious electron transfer [ 29 ] will then be established and two chelating five- and six-membered rings formed, which contributes to a better planarity and rigid of the J6/J7-Cu 2+ system. And stronger fluorescence intensity of the J6/J7-Cu 2+ system accompanied with the extended conjugated chain (the extended conjugation chain was labelled in blue in Figure 9 ) and better molecular planarity.…”

“…one nitrogen atoms will partly be provided to fulfill the empty electron orbits of Cu 2+ through intramolecular forces [27,28], though weaker than coordination bonds, an obvious electron transfer [29] will then be established and two chelating five-and six-membered rings formed, which contributes to a better planarity and rigid of the J6/J7-Cu 2+ system. And stronger fluorescence intensity of the J6/J7-Cu 2+ system accompanied with the extended conjugated chain (the extended conjugation chain was labelled in blue in Figure 9) and better molecular planarity.…”