75 research outputs found
Synthesis and characterizations of charge-transfer complexes of 1.8-naphthalimides with different acceptors
Synthesis and characterization of naphthalimide-functionalized polynorbornenes
ABSTRACT: Highly fluorescent and photostable (2-alkyl)-1H-benzo[de]isoquinoline-1,3(2H)-diones with a polymerizable norbornene scaffold have been synthesized and polymerized using ring-opening metathesis polymerization. The monomers presented herein could be polymerized in a living fashion, using different comonomers and different monomer ratios. All obtained materials showed good film-forming properties and bright fluorescence caused by the incorporated push–pull chromophores. Additionally, one of the monomers containing a methylpiperazine functionality showed protonation-dependent photoinduced electron transfer which opens up interesting applications for logic gates and sensing. GRAPHICAL ABSTRACT: [Image: see text
A novel fluorescent sensor for metal cations and protons based of bis-1,8-naphthalimide
International audienceA newly synthesized bis-1,8-naphthalimide aimed to increase its fluorescence intensity in the presence of protons or metal cations has been investigated. Its spectral photophysical characteristics in acetonitrile and chloroform solutions are described. The influence of metal cations (Zn2+, Ni2+, Ce3+, Co2+, Cu2+ and Ag+) and protons on the fluorescence intensity has been investigate with regard to obtain fluorescence sensors for this ions in the environment
Studying the photophysical properties of a polymerizable 1,8-naphthalimide dye and its copolymer with styrene as potential fluorescent sensors for metal cations
Grabchev, Ivo Dumas, Stephane Chovelon, Jean-MarcThe photophysical characteristics of a polymerizable 1,8-naphthalimide dye and its copolymer with styrene have been investigated. The functional properties of both low and high molecular weight fluorophores in the presence of different metal cations have been discussed with regard to their potential application as fluorosensors, for the metal cations and protons. In acetonitrile solution the monomeric 1,8-naphthalimide enhances its fluorescence emission in the presence of metal cations (Zn2+, Fe3+, Co2+, Pb2+, Cu2+, Ni2+, and Mn2+). In aqueous media the poly(St-co-MD) exhibits a selective response to Fe3+ cations. The monomeric and polymeric fluorophores also exhibit a considerable increase in their fluorescence intensity at acidic pH values (pH < 6) which suggest that they could be used as ON-OFF probes in analytical devices for signaling the presence of protons. Copyright (C) 2008 John Wile
A polyamidoamine dendrimer as a selective colorimetric and ratiometric fluorescent sensor for Li+ cations in alkali media
Grabchev, Ivo Dumas, Stephane Chovelon, Jean-Marcin a DMF + NaOH medium, a polyamidoamine dendrimer having sixteen 1,8-naphthalimide fragments in its periphery, formed a complex only with Li+ ions, detected by a colour change from red to yellow and by a significant increase in fluorescence intensity. The dendrimer can be used as a selective sensor for Li+ ions in the presence of other alkali ions such as Na+ or K+. (C) 2009 Elsevier Ltd. All rights reserved
Photophysical investigations on the sensor potential of novel, poly(propylenamine) dendrimers modified with 1,8-naphthalimide units
Grabchev, Ivo Staneva, Desislava Chovelon, Jean-MarcNovel poly(propylenamine) first and second generation dendrimers in which the periphery was modified with 1,8-naphthalimide units were synthesized. Acetonitrile solutions of the materials were subjected to photophysical investigation to evaluate their capability to detect metal cations, by monitoring changes in their absorption and fluorescence spectra in the presence of Ag+, Cu2+, Co2+, Ni2+, Fe3+ and Zn2+. The potential of the dendrimers to detect metal ion pollutants was estimated. (C) 2009 Elsevier Ltd. All rights reserved
Poly(amidoamine) dendrimer peripherally modified with 4-N,N-dimethylaminoethyleneamino-1,8-naphthalimide as a sensor of metal cations and protons
A new poly( amidoamine) dendrimer from second generation whose periphery comprises sixteen fluorescent 4-N,N-dimethylaminoethylamino-1,8-naphthalimide units has been synthesized and characterized. In DMF, the dendrimer shows sensitivity to the presence of Cu2+, Fe3+ and protons. The changes in the fluorescence intensity of the material are in opposite directions if acids or metals are present. Fluorescence enhancements (FE from 5 to 9 depending on solvent) are recorded when the photoinduced electron transfer ( PET) originating from the donating amine to the electron accepting naphthalimide is inhibited by the protonation of the N,N-dimethylamino groups. In the case of Cu2+ cations, a fluorescence quenching (FQ of 6) is first observed, followed by fluorescence partial restoration. In the Fe3+ case, the same behaviour is observed with a final FE of 2. The successive complexations of these cations by the dendrimer core and by the external rim of the dendrimer may explain the results
Self-Associated 1,8-Naphthalimide as a Selective Fluorescent Chemosensor for Detection of High pH in Aqueous Solutions and Their Hg2+ Contamination
A novel diamino triazine based 1,8-naphthalimide (NI-DAT) has been designed and synthesized. Its photophysical properties have been investigated in different solvents and its sensory capability evaluated. The fluorescence emission of NI-DAT is significantly impacted by the solvent polarity due to its inherent intramolecular charge transfer character. Moreover, the fluorescence emission quenched at higher pH as a result of photo-induced electron transfer (PET) from triazine moiety to 1,8-naphthalimide after cleaving hydrogen bonds in the self-associated dimers. Furthermore, the new chemosensor exhibited a good selectivity and sensitivity towards Hg2+ among all the used various cations and anions in the aqueous solution of ethanol (5:1, v/v, pH = 7.2, Tampon buffer). NI-DAT emission at 540 nm was quenched remarkably only by Hg2+, even in the presence of other cations or anions as interfering analytes. Job’s plot revealed a 2:1 stoichiometric ratio for NI-DAT/Hg2+ complex, respectively
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