A new intramolecular charge transfer receptor as a selective ratiometric ‘off–on’ sensor for Zn2+

Mashraqui, Sabir H.; Khan, Tabrez; Sundaram, Subramanian; Betkar, Rupesh; Chandiramani, Mukesh

doi:10.1016/j.tetlet.2007.09.163

Cited by 32 publications

(6 citation statements)

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“…As direct reaction of AgNO 3 with H 2 L does not give a Ag-complex, the possibility of displacement mode can be ruled out. It suggested that the fluorescence enhancement possibly arises from charge transfer through weak interaction between 1 and Ag + ion. , The Job’s plot analysis (Supporting Information, Figure S9) shows 1:2 stoichiometry between 1 and Ag + ion and the association constant ( K a ) from a B−H plot based on emission titration studies (Supporting Information, Figure S10) is 8.05 log K a . Although the color of solutions containing H 2 L, 1 , 3 , and 4 under UV light are not significantly different, however, the fluorescence intensity of 1 diminishes and enhances in the presence of Cu 2+ and Ag + ions, respectively (Figure a, inset).…”

Section: Resultsmentioning

confidence: 86%

“…A straight line obtained in the S−V plot suggested dynamic quenching (Supporting Information, Figure S10). The association constants ( K a ) deduced for 1:1 stoichiometry, based on emission and absorption titration studies are 3.29 and 3.54 log K a , respectively (Supporting Information, Figure S11). It was further observed that an increase in the time interval for addition of Cu 2+ leads to insignificant changes in the absorption as well as fluorescence spectral patterns.…”

Section: Resultsmentioning

confidence: 99%

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Fluorescent Zinc(II) Complex Exhibiting “On-Off-On” Switching Toward Cu²⁺ and Ag⁺ Ions

et al. 2011

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Binuclear zinc(II) and copper(II) complexes based on a new Schiff base ligand N,N'-bis(2-hydroxybenzilidene)-2,4,6-trimethylbenzene-1,3-diamine (H(2)L) have been synthesized. The ligand H(2)L and complexes under investigation have been characterized by elemental analyses, spectral (FT-IR, (1)H, (13)C NMR, ESI-MS, electronic absorption, emission), and electrochemical studies. The structures of H(2)L and complexes [{Zn(C(23)H(18)N(2)O(2))}(2)] (1) and [{Cu(C(23)H(18)N(2)O(2))}(2)]·H(2)O (2) have been determined crystallographically. Selective "On-Off-On" switching behavior of the fluorescent complex 1 has been studied. The fluorescence intensity of 1 quenches (turns-off) upon addition of Cu(2+), while enhances (turns-on) in the presence of Ag(+) ions. The mechanisms of "On-Off-On" signaling have been supported by (1)H NMR, ESI-MS, electronic absorption, and emission spectral studies. Job's plot analysis supported 1:1 and 1:2 stoichiometries for Cu(2+) and Ag(+) ions, respectively. Association and quenching constants have been estimated by the Benesi-Hildebrand method and Stern-Volmer plot. Moreover, 1 mimics a molecular keypad lock that follows correct chemical input order to give maximum output signal.

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Section: Resultsmentioning

confidence: 86%

Section: Resultsmentioning

confidence: 99%

Fluorescent Zinc(II) Complex Exhibiting “On-Off-On” Switching Toward Cu²⁺ and Ag⁺ Ions

et al. 2011

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“…Association constants for 4 + Hg 2+ and 4 + Pb 2+ have been calculated by the Benesi–Hildebrand method and found to be 1.39 × 10 4 and 2.52 × 10 2 mol –1 , respectively (Figure S17 in the SI). The selectivity of 4 toward Pb 2+ was also examined by interference studies, and it was observed that none of the tested metal ions (10.0 equiv) leads to significant changes except Hg 2+ , which induces considerable fluorescence quenching (37%; Figure S16b in the SI). The overall results suggest that 4 selectively detects the Hg 2+ and Pb 2+ ions with distinct output signaling and shows higher selectivity for Hg 2+ over Pb 2+ in aqueous media (Figures S12 and S16 in the SI).…”

Section: Electronic Spectroscopymentioning

confidence: 99%

Synthesis and Characterization of Electroactive Ferrocene Derivatives: Ferrocenylimidazoquinazoline as a Multichannel Chemosensor Selectively for Hg²⁺ and Pb²⁺ Ions in an Aqueous Environment

et al. 2011

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The synthesis and characterization of ferrocene (Fc) derivatives 4-[2,5-diferrocenyl-4-(4-pyridyl)imidazolidin-1-ylmethyl]pyridine (1), ferrocenylmethylenepyridin-3-ylmethylamine (2), N,N'-bis(ferrocenylmethylene)-2,4,6-trimethylbenzene-1,3-diamine (3), and 6-ferrocenyl-5,6-dihydro[4,5]imidazo[1,2-c]quinazoline (4) have been described. Structures of 1, 2, and 4 have been determined by single-crystal X-ray diffraction analyses. At 25 °C, 1-3 are nonfluorescent, while 4 displays moderate fluorescence and chromogenic, fluorogenic, and electrochemical sensing selectively toward Hg(2+) and Pb(2+) ions. Association constants (K(a)) for Hg(2+) and Pb(2+) have been determined by the Benesi-Hildebrand method. Job's plot analysis supported 1:1 and 1:2 stoichiometries for Hg(2+) and Pb(2+) ions. Cyclic voltammograms of 1-4 exhibited reversible waves corresponding to a ferrocene/ferrocenium couple. The wave associated with 4 (+0.0263 V) exhibited positive (ΔE(pa) = 0.136 V) and negative (ΔE(pa) = 0.025 V) shifts in the presence of Hg(2+) and Pb(2+) ions, respectively. The mode of interaction between metal ions and 4 has been supported by (1)H NMR spectroscopy and mass spectrometry studies and verified by theoretical studies. It presents the first report dealing with ferrocene-substituted quinazoline as a multichannel chemosensor for Hg(2+)/Pb(2+) ions.

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“…Generally, an ICT system contains an electron‐donating group and an electron‐withdrawing group, and it undergoes ICT from the donor to the acceptor upon photo‐excitation. In fact, ICT is an effective signalling mechanism employed in the design of ratiometric fluorescent probes, and in recent years several probes and chemosensors have been developed via modulation of the ICT efficiency of the probe upon interaction with an analyte . One typical way to achieve this is to directly engage the charge of an analyte with the electron donating or withdrawing group of the probe in the binding process .…”

Section: Introductionmentioning

confidence: 99%

A ratiometric fluorescent probe for bisulphite anion, employing intramolecular charge transfer

Wang

Yang

2012

Luminescence

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4-(1H-benzimidazol-2-yl)benzaldehyde (1) has been developed as a new ratiometric fluorescent probe for bisulphite, based on the modulation of intramolecular charge transfer (ICT). Upon mixing with bisulphite in aqueous ethanol, an aldehyde-bisulphite adduct was formed and the ICT of the probe was switched off, which resulted in a ratiometric fluorescence response with an enhancement of the ratios of emission intensities at 368 and 498 nm. The detection range of the probe for bisulphite is in the 2.0-200 µmol/L concentration range and the detection limit is 0.4 µmol/L. Probe 1 produces a ratiometric fluorescent response to bisulphite with a marked emission wavelength shift (130 nm) and displays high selectivity for bisulphite over other anions.

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A new intramolecular charge transfer receptor as a selective ratiometric ‘off–on’ sensor for Zn2+

Cited by 32 publications

References 50 publications

Fluorescent Zinc(II) Complex Exhibiting “On-Off-On” Switching Toward Cu²⁺ and Ag⁺ Ions

Fluorescent Zinc(II) Complex Exhibiting “On-Off-On” Switching Toward Cu²⁺ and Ag⁺ Ions

Synthesis and Characterization of Electroactive Ferrocene Derivatives: Ferrocenylimidazoquinazoline as a Multichannel Chemosensor Selectively for Hg²⁺ and Pb²⁺ Ions in an Aqueous Environment

A ratiometric fluorescent probe for bisulphite anion, employing intramolecular charge transfer

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A new intramolecular charge transfer receptor as a selective ratiometric ‘off–on’ sensor for Zn2+

Cited by 32 publications

References 50 publications

Fluorescent Zinc(II) Complex Exhibiting “On-Off-On” Switching Toward Cu2+ and Ag+ Ions

Fluorescent Zinc(II) Complex Exhibiting “On-Off-On” Switching Toward Cu2+ and Ag+ Ions

Synthesis and Characterization of Electroactive Ferrocene Derivatives: Ferrocenylimidazoquinazoline as a Multichannel Chemosensor Selectively for Hg2+ and Pb2+ Ions in an Aqueous Environment

A ratiometric fluorescent probe for bisulphite anion, employing intramolecular charge transfer

Contact Info

Product

Resources

About

Fluorescent Zinc(II) Complex Exhibiting “On-Off-On” Switching Toward Cu²⁺ and Ag⁺ Ions

Fluorescent Zinc(II) Complex Exhibiting “On-Off-On” Switching Toward Cu²⁺ and Ag⁺ Ions

Synthesis and Characterization of Electroactive Ferrocene Derivatives: Ferrocenylimidazoquinazoline as a Multichannel Chemosensor Selectively for Hg²⁺ and Pb²⁺ Ions in an Aqueous Environment