65 research outputs found

    Synthesis and characterization of naphthalimide-functionalized polynorbornenes

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    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

    Studying the photophysical properties of a polymerizable 1,8-naphthalimide dye and its copolymer with styrene as potential fluorescent sensors for metal cations

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    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

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    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

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    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

    Self-Associated 1,8-Naphthalimide as a Selective Fluorescent Chemosensor for Detection of High pH in Aqueous Solutions and Their Hg2+ Contamination

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    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&rsquo;s plot revealed a 2:1 stoichiometric ratio for NI-DAT/Hg2+ complex, respectively

    Synthesis and Characterization of a New PAMAM Metallodendrimer for Antimicrobial Modification of Cotton Fabric

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    The synthesis and spectral characterization of a new PAMAM metallodendrimer modified with four 4-hexylamino-1,8-naphthalimide units was described. The chemical structure of metallodendrimer has been analyzed with Fourier transform infrared spectroscopy, electronic, nuclear magnetic resonance spectroscopy, and scanning electron microscopy (SEM) analysis. The antimicrobial activity of PAMAM dendrimer and its Zn complex [Zn(D)(NO)] was investigated in agar medium and in meat-peptone broth against several pathogenic bacteria and yeasts. The antimicrobial screening showed good inhibition activity of the compounds better expressed against the test Gram-positive bacteria and yeasts. The antimicrobial efficacy of cotton fabrics treated with each of the dendrimers was evaluated, and their anti-adhesive and biofilm inhibiting potential was analyzed by SEM. The complex [Zn(D)(NO)] showed stronger antimicrobial and biofilm inhibiting abilities than those of the ligand. The cytotoxicity effect of the dendrimers was also investigated in vitro in model HEp-2 cell line.The authors acknowledge Grant No H09/03-2016, Fund “Scientific Research”, Ministry of Education and Science of Bulgaria. IG and PB also acknowledge COST CA15114 “Anti-MIcrobial Coating Innovations to prevent infectious diseases (AMICI)Peer Reviewe
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