Polyhalogenated Ethers
US Patent: 7393961 B2
Date: Jul. 1, 2008
Inventors: G. Fontana, W. Navarrini
published July 1, 2008
published June 1, 2008
posted in Papers - 2008
Propylene carbonate uptake and conductivity of lithiated short side chain perfluorinated sulfonic ionomeric membranes
Author(s): Navarrini, Walter; Scrosati, Bruno; Panero, Stefania; Sanguineti, Aldo; Alessandro, Ghielmi; Paolo, Fossati.
Source: CHIMICA OGGI-CHEMISTRY TODAY
Volume: 26 Issue: 3 Supplement: 1 Pages: 22-25 Published: MAY-JUN 2008
ABSTRACT:
Short Side Chain (SSC) ion-conducting polymers have revealed a better electrochemical behaviour compared to the long-side-chain (LSC) NAFION (R)-like polymers in the Polymer Electrolyte Membrane Fuel Cell (PEMFC) application (1). The relevance of the lithium form of HYFLON (R) ION as polymer electrolyte for lithium ion batteries has also been investigated. Starting from these SSC ionomers and utilising a particularly straightforward methodology for the preparation and dehydration of the lithium ion membrane in nonaqueous media, it has been possible to achieve a high ionic conductivity in the range of 10-3 S/cm at room temperature(2). The high concentration of lithium ions and the high polymer swelling in propylene carbonate solvent are not sufficient to explain the high ionic conductivity observed.
published May 20, 2008
Process for the Preparation of (Per)Fluorinated Mono-Functional Carbonyl Compounds
US Patent: 7375253 B2
Date: May 20, 2008
Inventors: G. Fontana, W. Navarrini
published April 1, 2008
posted in Papers - 2008
Lithiated short side chain perfluorinated sulfonic ionomeric membranes: Water content and conductivity
Author(s): Navarrini, Walter; Scrosati, Bruno; Panero, Stefania; Ghielmi, Alessandro; SSanguineti, Aldo); Geniram, Giuliana.
Source: JOURNAL OF POWER SOURCES
Volume: 178 Issue: 2 Pages: 783-788
DOI: 10.1016/j.jpowsour.2007.09.110 Published: APR 1 2008
ABSTRACT:
In view of possible applications as single-ion electrolyte for lithium batteries, some aspects of the lithium form of Hyflon Ion ionomer, a sulfonic short side chain (SSC) electrolyte, have been investigated. The synthesis of the ionomer and the successive membrane preparation is reported. An appropriate methodology for the direct salification of the ionomeric membrane from the SO2F form to lithium salt, using lithium hydroxide in absence of organic solvent has been found. Utilizing these SSC lithium ionomer membranes and though a particular methodology for the dehydration of the lithium ion membrane in non-aqueous media, it has been possible to achieve an ionic conductivity of 10(-3) S cm(-1) at room temperature [W. Navarrini, S. Panero, B. Scrosati, A. Sanguineti, European Patent 1,403,958 A1 (2003)]. Surprisingly it was observed that the membrane ionic conductivity depends on the dehydration methodologies adopted.
http://www.sciencedirect.com/science/article/pii/S0378775307021775
published January 22, 2008
Process for the Preparation of (Per) Fluorinated Mono-Functional Carbonyl Compounds
US Patent: 7321062 B2
Date: Jan. 22, 2008
Inventors: G. Fontana, W. Navarrini
published January 1, 2008
posted in Papers - 2008
“Little barrel, good wine?”
Author(s): Navarrini, Walter
Source: CHIMICA OGGI-CHEMISTRY TODAY
Volume: 26 Issue: 1 Pages: 2-2 Published: JAN-FEB 2008
published September 23, 2007
posted in Posters
15th European Symposium on Fluorine Chemistry – Prague – July 15-20, 2007
New Advances in Perfluoroalkytation of Aromatics: Products and Mechanism
Sansotera a, P. Metrangolo a, W. Navarrini a, G. Resnati a, I. Wlassics b
a Dip-CMIC ”Giulio Natta”, Politecnico di Milano, via Mancinelli 7, 20131 Milan, Italy;
b R&D Centre, Solvay Solexis, viale Lombardia 20, 20021 Bollate (MI), Italy
E-mail: maurizio.sansotera@polimi.it; walter.navarrini@polimi.it
Thermal decomposition of perfluorodiacyl peroxides in the presence of aromatic compounds leads to the synthesis of perfluoroalkylated aromatic derivatives. C3 and C4-perfluorodiacyl peroxides have been synthesized starting from C3 and C4-perfluoroacyl halides with H2O2 in alkaline conditions and have been employed in reactions with several aromatic substrates. The capability of perfluorodiacyl peroxides to generate perfluoroalkyl free radicals is at the basis of the perfluoroalkylation process. Perfluoroalkyl radical reacts with the aryl via an electron-transfer propagation process. During the formation of the perfluoroalkylated intermediate the aromatic substrate loses its aromaticity and another molecule of peroxide oxidizes the intermediate. Finally a proton removal restores the aromaticity. Competitive mechanistic pathways are responsible for the perfluoroalkyl radical formation: primarily the concerted dissociation with a three-bond fission, and secondarily the stepwise decomposition through primary homolytic cleavage of O-O peroxidic bond and subsequent decarboxylation. Stability of the oncoming radicals and temperature are the important parameters to discriminate the decomposition pathway. The analyses of reaction main-products and by-products allowed to draw a more complete mechanism pathway that can be applied to the whole family of aromatic compounds.
published June 4, 2007
posted in Papers - 2007
Dipyridinocalixcrown/diiodoperfluorocarbon binary host systems for CsI: structural studies and fluorous phase extraction of caesium
Author(s): Gattuso, Giuseppe; Pappalardo, Andrea; Parisi, Melchiorre F.; Pisagatti, Ilenia; Crea, Francesco; Liantonio, Rosalba; Metrangolo, Pierangelo; Navarrini, Walter; Resnati, Giuseppe; Pilati, Tullio; Pappalardo, Sebastiano.
Source: TETRAHEDRON
Volume: 63 Issue: 23 Pages: 4951-4958
DOI: 10.1016/j.tet.2007.03.136
Published: JUN 4 2007
ABSTRACT:
A mixture of partial cone 2,4-bis[(2-pyridylmethyl)oxy]-(1,3)-p-tert-butylcalix[4]crown-6, hexadecafluoro-1,8-diiodooctane and CsI in EtOH produces a crystalline ‘supramolecular salt’. In the solid state the caesium ion of the ‘supercation’ is encapsulated inside the cavity created by the crown ether loop, the picolyl and the inverted phenyl moieties, while the two iodide ions of the ‘superanion’ form a discrete five-component aggregate held together by co-existing hydrogen and halogen bonds. Similar calix/CsI/iodofluorocarbon adducts are shown to exist also in solution. In a prototypical study, a combination of this calixcrown and liquid octafluoro-1,4-diiodobutane acts as an effective ‘binary host’ system for the selective extraction of CsI from aqueous to fluorous phase.
http://www.sciencedirect.com/science/article/pii/S0040402007005698
published February 1, 2007
posted in Papers - 2007
ASP studies on fluorine in biomedicine: two innovative applications
Author(s): Navarrini, Walter; (Canesi, Eleonora; Cantini, Marco; Resnati, Giuseppe; Metrangolo, Pierangelo; Ugger, Fulvio; Arcella, Vincenzo; Casati, Alessandro; Masella, Marco; Guala, Carlo; Ranzoni, Andrea; Sallemi, Livia; Sciacca, Beniamino; Scotti, Filippo.
Source: CHIMICA OGGI-CHEMISTRY TODAY
Volume: 25 Issue: 3 Pages: 48-50 Published: 2007
ABSTRACT:
Through the multiddiciplinary ASP project, some students of Politacnico di Milano and Politecnico di Torino had the possibility to deal with the peculiar properties of fluorinated compounds. In particular, we investigated the possible exploitation of these features for biomedical applications, focusing on two specific subjects: diagnostic tools and drug delivery. Perfluoroethers revealed to be suitable materials or these uses, because of a cohesive energy density and an enthalpy of vaporization lower than those of hydrogenated ethers.
published January 9, 2007
Fluorovinyl Ethers and Polymers Obtainable Therefrom
US Patent: 7160967 B2
Date: Jan. 9, 2007
Inventor: W. Navarrini
published January 1, 2007
posted in Papers - 2007
Perfluoroalkylation of aromatic compounds with perfluorodiacyl peroxides
Author(s): Resnati, Giuseppe; Wlassics, Ivan; Sansotera, Maurizio; Metrangolo, Pierangelo; Navarrini, Walter.
Source: CHIMICA OGGI-CHEMISTRY TODAY
Volume: 25 Issue: 3 Supplement: 1 Pages: 23-25 Published: 2007.
ABSTRACT:
Perfluoroalkylation of aromatics obtained by perfluorodiacyl peroxide decomposition has been studied andrationalised. Products and by-products formed are in agreement with the proposed free radical/one electron transfer mechanism.
published November 28, 2006
Process for Preparing Hydrofluoroethers
US Patent: 7141704 B2
Date: Nov. 28, 2006
Inventors: W. Navarrini, M. Galimberti, G. Fontana
published November 14, 2006
Perfluorodiacylperoxides as Polymerization Iniziators
US Patent: 7135599 B2
Date: Nov. 14, 2006
Inventors: W. Navarrini, M. Galimberti
published August 9, 2006
