Lionel Massi
University of Nice Sophia Antipolis
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Publication
Featured researches published by Lionel Massi.
International Journal of Antimicrobial Agents | 2003
Lionel Massi; Frédéric Guittard; Serge Geribaldi; R Levy; Y Duccini
Four series of new highly fluorinated bisammoniums (Quaterfluo Tx, Quaterfluo Bx, Quaterfluo Cx, Quaterfluo Dx) were tested to evaluate their anti-bacterial and anti-fungal properties. Four microbial strains were used to perform the study: Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans and Aspergillus niger. The antimicrobial efficacy was measured by bacterial and fungal growth inhibition expressed as minimal inhibitory concentration (MIC) values. The Quaterfluo Tx series had very good antimicrobial activity, particularly against Gram-negative bacteria. A speed of kill test carried out with Quaterfluo T3 showed bactericidal activity. The introduction of perfluorinated chains into the quaternary ammonium surfactant structure leads to particularly active antimicrobial agents which not only have bacteriostatic properties but which could be also powerful bactericides.
Thin Solid Films | 2002
Zineb Mekhalif; Lionel Massi; Frédéric Guittard; Serge Geribaldi; Joseph Delhalle
Two types of zinc substrates, mechanically polished and electrochemically reduced, modified with n-dodecanethiol and 3-perfluorooctyl-propanethiol have been evaluated by X-ray photoelectron spectroscopy. For both types of organothiols, it is found that the electrochemically reduced substrates lead to modified surfaces of much better quality than those obtained on the mechanically polished substrates.
Rapid Communications in Mass Spectrometry | 2010
Ilaria Monfardini; Lionel Massi; Pascale Tremel; Agnès Hauville; Sandra Olivero; Elisabet Duñach; Jean-François Gal
Trifluoromethylsulfonate (triflate) and bis(trifluoromethylsulfonyl)imide (triflimide) salts, well-known Lewis acid catalysts, present some difficulty in their characterization. By using nitromethane as the solvent, useful electrospray mass spectra in positive and negative ion mode were obtained for salts of metals in oxidation states +2 and +3. In positive mode, addition of a strong Lewis base (triphenylphosphine oxide, TPPO), capable of displacing a triflate (TfO(-)) or a triflimide (Tf(2)N(-)) anion, is necessary for obtaining useful spectra. Under these conditions of solvent and added ligand, the most abundant ions were [M(2+)(A(-))(TPPO)(2)](+) or [M(3+)(A(-))(2)(TPPO)(2)](+) with A(-) = TfO(-) or Tf(2)N(-). The MS/MS spectra of these diagnostic ions provide additional analytical information. The breakdown curves, in the form of % dissociated as a function of the ion activation energy, offer a mean for investigating the bonding in these ions.
Journal of Mass Spectrometry | 2010
Charly Mayeux; Jean-François Gal; Laurence Charles; Lionel Massi; Pierre-Charles Maria; Jaana Tammiku-Taul; Peeter Burk
Collision-induced dissociation (CID) of the Cs(+) heterodimer adducts of the nitrate anion (NO(3)(-)) and a variety of substituted benzoates (XBenz(-)) [(XBenz(-))(Cs(+))(NO(3)(-))](-) produces essentially nitrate and benzoate ions. A plot of the natural logarithm of their intensity ratio, ln[I (NO(3)(-))/I(XBenz(-))], versus the calculated cesium cation affinity (DFT B3LYP) of the substituted benzoate ions (equivalent to the enthalpy of heterolytic dissociation of the salt) is reasonably linear. This suggests that the kinetic method can be used as a source of data on the intrinsic interaction between the anionic and the cationic moieties in a salt.
Journal of the American Society for Mass Spectrometry | 2012
Jean-François Gal; Claudio Iacobucci; Ilaria Monfardini; Lionel Massi; Elisabet Duñach; Sandra Olivero
The interaction between two Lewis “superacid” catalysts Zn(OTf)2 and In(OTf)3 and series of amide and phosphate ligands is quantitatively characterized by electrospray ionization mass spectrometry (ESI-MS). A specific feature of the ESI-MS spectra of the mixture of metal triflates and Lewis bases is the formation of ionic adducts resulting from the displacement of one triflate anion by two neutral ligands. A ligand competition model is developed, which describes the relative intensities of the ionic adducts as a function of relative ligand concentrations. The relative affinities deduced from the ligand competition method are combined in an affinity scale for the metal triflate.
Journal of the American Society for Mass Spectrometry | 2009
Charly Mayeux; Jaana Tammiku-Taul; Lionel Massi; Peeter Burk; Pierre-Charles Maria; Jean-François Gal
Humic substances (HS), including humic and fulvic acids, play a significant role in the fate of metals in soils. The interaction of metal cations with HS occurs predominantly through the ionized (anionic) acidic functions. In the context of the effect of HS on transport of radioactive cesium isotopes in soils, a study of the interaction between the cesium cation and model carboxylic acids was undertaken. Structure and energetics of the adducts formed between Cs+ and cesium carboxylate salts [Cs+RCOO−] were studied by the kinetic method and density functional theory (DFT). Clusters generated by electrospray ionization mass spectrometry from mixtures of a cesium salt (nitrate, iodide, trifluoroacetate) and carboxylic acids were quantitatively studied by CID. By combining the results of the kinetic method and the energetic data from DFT calculations, a scale of cesium cation affinity, CsCA, was built for 33 cesium carboxylates representing the first scale of cation affinity of molecular salts. The structural effects on the CsCA values are discussed.
ChemPhysChem | 2017
Guillaume Compain; Lionel Massi; Jean-François Gal; Elisabet Duñach
Metal triflates, often called Lewis superacids, are potent catalysts for organic synthesis. However, the reactivity of a given Lewis superacid toward a given base is difficult to anticipate. A systematic screening of catalysts is often necessary when developing synthetic methodologies. Presented herein is the development of quantitative reactivity and bond strength scales by using mass spectrometry (MS). By applying a collision-induced dissociation (CID) technique to the adducts formed between Lewis superacids Al(OTf)3 or In(OTf)3 with a series of amides bases, including monodentate and bidentate ligands, different dissociation pathways were observed. Quantitative relative energy scales were established by performing energy-resolved mass spectrometry (ERMS) analysis on the adducts. ERMS of the adducts affords a bond strength scale when the fragmentation leads to the loss of a ligand, and reactivity scales when the dissociation leads to the C-F bond activation of one triflate anion or the deprotonation of the ligand. Al(OTf)3 was found to bind stronger to amides than In(OTf)3 and to provide the most reactive adducts.
Rapid Communications in Mass Spectrometry | 2011
C. Zerbib; Sonia Amigoni; E. Taffin de Givenchy; Lionel Massi; I. Precheur; Frédéric Guittard
We have investigated the synthesis of a new antifungal agent with a polymerisable moiety for the prevention of denture stomatisis. Nystatin (antifungal polyene) is modified in one step by reaction with isocyanatoethylmethacrylate to afford a new polymerisable antifungal agent in good yield (90%). In order to prove the monografting of the acrylate derivative and to localise the new group in the skeleton of the molecule, a rapid and efficient analytical method involving electrospray ionisation mass spectrometry (ESI-MS) was developed for the study. In view of the structures of such antifungal agents, their complexation with metal cations was investigated by Coordination-Ion Spray Mass Spectrometry (CIS-MS). This mass spectrometry study covers two aspects: improving the MS signal to overcome the low ionisation efficiency in ESI-MS and exploring the complexation behaviour of the induced structure to optimise the antifungal properties.
International Journal of Mass Spectrometry | 2007
Jean-François Gal; Pierre-Charles Maria; Lionel Massi; Charly Mayeux; Peeter Burk; Jaana Tammiku-Taul
European Journal of Medicinal Chemistry | 2003
Lionel Massi; Frédéric Guittard; Richard Levy; Yves Duccini; Serge Geribaldi