Home  /  Publications
published November 7, 1995
posted in Papers - 1995
author

EPR AND ENDOR OF PERFLUOROALKYL RADICAL INTERMEDIATES IN THE REACTION BETWEEN PERFLUOROHYPOFLUORITES AND PERFLUOROALKENES

Author(s): CONTI, F; CORVAJA, C; CREMONESE, F; NAVARRINI, W; TORTELLI, V

Source: JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS

Volume: 91 Issue: 21 Pages: 3813-3820

DOI: 10.1039/ft9959103813 Published: NOV 7 1995

ABSTRACT:

EPR and ENDOR spectra of the reaction products of sterically hindered perfluoroalkenes with perfluoromethyl hypofluorite and with the perfluoroether hypofluorite X(CF2O)(n)(CF2CF2O)(m)CF2OF, where X is either OCF3 or a second hypofluorite group OCF2-OF, have been recorded. Tertiary and secondary free radicals are produced by the addition to the alkene double bond of a fluorine atom or of the partner radical formed by the homolysis of the hypofluorite O-F bond. Analysis of the spectra reveals that hyperfine splitting by F-19 nuclei in the gamma and delta positions, and even further from the radical centre, contribute spectra. The alpha- and beta-F-19 hyperfine splitting are discussed in relation to the radical structure and conformation. The beta-F-19 splittings are accounted for by the well known equation a(F)(beta) = B cos(2)(theta); different values of the constant B have to be used according to the number of beta-fluorine substituents bonded to the same alpha-carbon.

http://pubs.rsc.org/en/Content/ArticleLanding/1995/FT/ft9959103813#!divAbstract

published October 6, 1995
posted in Papers - 1995
author

RELATIVE RATE CONSTANTS FOR THE REACTIONS OF CF3OF WITH OLEFINS IN SOLUTION

 

Author(s):NAVARRINI, W; RUSSO, A; TORTELLI, V.

Source: JOURNAL OF ORGANIC CHEMISTRY

Volume: 60 Issue: 20 Pages: 6441-6443

DOI: 10.1021/jo00125a033 Published: OCT 6 1995

ABSTRACT:

The addition reactions of CF3OF to chloro fluoro olefins have been studied in solution at low temperature (-78, -105 degrees C), and their relative rate constants have been determined using the kinetic approach of competition reactions. The reactivity and regio- and stereoselectivity are consistent with a free radical chain-propagating reaction in which the alkenes are attacked by the CF3O. radical generated by homolitic cleavage of the O-F bond in the CF3OF molecule.

http://pubs.acs.org/doi/abs/10.1021/jo00125a033

published September 1, 1995
posted in Papers - 1995
author

THE REACTION OF CF3OOCF2OF WITH FLUOROOLEFINS

 

Author(s): RUSSO, A; MONTANARI, V; NAVARRINI, W; DESMARTEAU, DD.

Source: JOURNAL OF FLUORINE CHEMISTRY

Volume: 74 Issue: 1 Pages: 83-87

DOI: 10.1016/0022-1139(95)03243-7 Published: SEP 1995.

ABSTRACT

The reaction of fluoroxydifluoromethyl trifluoromethyl peroxide, CF3OOCF2OF (1), with fluoroolefins leads to the formation of novel fluorinated peroxides as major products. When 1 was added to 1,2-dichloro-1,2-difluoroethylene, CFCl=CFCl, under controlled conditions,the formation of 4,5-dichloro-2,2,4,5-tetrafluoro-1,3-dioxolane was also observed. A mechanism is proposed to rationalize these results.

http://www.sciencedirect.com/science/article/pii/0022113995032437

published August 11, 1995
posted in Patents - 1995
author

Phosphazene derivatives and use of same as stabilizers for oils and greases based on perfluoropolyethers

US Patent: 5441655

Date: Aug. 08 1995

Inventors: Odello Paolo, Navarrini Walter,Chambers Richard D., Corti Costante

US5441655 – PDF


published May 15, 1995
posted in Oxyfluorides, Papers - 1995
author

THE ADDITION OF TRIFLUOROMETHYLHYPOFLUORITE TO HEXAFLUOROPROPENE DIMERS

Author(s): CORVAJA, C; CREMONESE, F; NAVARRINI, W; TONELLI, C; TORTELLI, V.

Source: TETRAHEDRON LETTERS

Volume: 36 Issue: 20 Pages: 3543-3546

DOI: 10.1016/0040-4039(95)00553-O Published: MAY 15 1995

ABSTRACT:

The reaction of trifluomethylhypofluorite with the two anionic dimers of hexafluoropropene leads to the trifluoromethylether adducts in excellent yield. The radical intermediates of the reaction have been detected using the EPR technique.

http://www.sciencedirect.com/science/article/pii/004040399500553O

published April 1, 1995
posted in Papers - 1995
author

NOVEL MOLECULES AND INDUSTRIAL-PROCESSES INSPIRED BY CADY,G.H. RESEARCH ON HYPOFLUORITES

Author(s):DESMARTEAU, DD; NAVARRINI, W; ZEDDA, A; RUSSO, A; MONTANARI, V.

Source:JOURNAL OF FLUORINE CHEMISTRY

Volume: 71 Issue: 2 Pages: 169-170

DOI: 10.1016/0022-1139(94)06008-A Published: APR 1995

http://www.sciencedirect.com/science/article/pii/002211399406008A

published March 21, 1995
posted in Oxyfluorides, Patents - 1995
author

Process for Preparing Perfluoro-2-Methyl-4-Methoxypentane

US Patent: 5399779

Date: Mar. 21, 1995

Inventors: V. Tortelli, C. Tonelli, W. Navarrini, S. Fontana

US5399779 – PDF

published March 1, 1995
posted in Papers - 1995
author

A new approach to the synthesis of 2,2-difluoro-1,3-dioxolanes

 

 

Author(s):NAVARRINI, W;BRAGANTE, L;FONTANA, S;TORTELLI, V; ZEDDA, A.

Source:JOURNAL OF FLUORINE CHEMISTRY

Volume: 71 Issue: 1 Pages: 111-117

DOI: 10.1016/0022-1139(94)03167-X Published: MAR 1995

ABSTRACT:

A direct and versatile way to prepare halogenated 2,2-difluoro-1,3-dioxolanes through the addition of bis-(fluoroxy)difluoromethane (BDM) to halogenated alkenes (CF2=CFCF3, CF2=CFOCF2CF3, CF2=CHCF3, CF3CF=CFCF3, CFCl=CFCl, CFBr=CFBr, CCl2=CCl2, CHCl=CCl2, CHCl=CHCl, CH2=CHCl, CF2=CFCl, (CF3)(2)CFCF=CFCF3, CF2=CFBr, CF2=CF2) has been discovered.

http://www.sciencedirect.com/science/article/pii/002211399403167X

published December 20, 1994
posted in Oxyfluorides, Patents - 1994
author

Process for Preparing Perfluoroalkoxysulphonic Compounds

US Patent: 5374770

Date: Dec. 20, 1994

Inventors: W. Navarrini, V. Montanari, A. M. Staccione

US5374770 – PDF

published May 1, 1994
posted in Papers - 1994
author

MODEL COMPOUNDS AND MONOMERS DERIVED FROM 1,1-DIFLUOROETHENE

Author(s):CHAMBERS, RD; APSEY, GC; ODELLO, P; MOGGI, G; NAVARRINI, W.

Source:MACROMOLECULAR SYMPOSIA

Volume 82, Issue 1, pages 33-50, May 1994

ABSTRACT:

Saturated model compounds, related to elastomers that are derived from co-polymers of CH2=CF2/CF2=CFCF3, have been synthesised and studied. Unsaturated compounds were obtained by both base- and Lewis-acid induced processes. Some reactions with antimony pentafluoride lead to remarkably stable carbocations, and even di-cations, and the nmr data for these systems is revealing about structure. Polyconjugated polymers may be obtained by this procedure. Preliminary studies are described, relating to the incorporation of crowded monomers into fluorocarbon polymers, ultimately, as a means of initiating cross-linking processes for curing elastomers.

http://onlinelibrary.wiley.com/doi/10.1002/masy.19940820105/abstract;jsessionid=E7184FE1AA06A64E7389B89E95CFDEFC.f02t03
published March 22, 1994
posted in Patents - 1994
author

Process for preparing 1,3-dioxoles

US Patent: 5296617

Date: March. 22 1994

Inventors: Navarrini Walter, Fontana, Simonetta

US5296617 – PDF

published March 13, 1994
posted in Oxyfluorides, Papers - 1994
author

NOVEL MOLECULES AND INDUSTRIAL-PROCESSES INSPIRED BY CADY,G.H. RESEARCH ON HYPOFLUORITES

Author(s): DESMARTEAU, DD ; NAVARRINI, W; ZEDDA, A; RUSSO; MONTANARI, V

Source: ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY

Volume: 207 Pages:12 FLUOPart:1Published: MAR 13 1994

published March 3, 1994
posted in Papers - 1994
author

Electrochemical Behavior and EPR of Radical Anions of Perfluoroalkyl-Substituted Olefins

Carlo Corvaja, Giuseppe Farnia, Gianni Formenton, Walter Navarrini, Giancarlo Sandona, Vito Tortelli

Source: JOURNAL OF PHYSICAL CHEMISTRY

Volume: 98 Issue: 9 Pages: 2307-2313

DOI: 10.1021/j100060a017

ABSTRACT:
Some perfluoroalkylolefins are shown to undergo electrochemical one-electron reduction to the corresponding radical anions at potential values which strongly depend on the structure of the substituents. In these cases the voltammetric reduction peak is chemically reversible, and a further one-electron transfer, affording the corresponding dianions, is detected at more negative potentials. For these substrates, at appropriate temperatures, the free radical anions are stable enough to be accumulated by macroscale electrolysis and investigated by EPR. The spectra are characterized by fairly large hyperfine couplings of F-19 in alpha, beta, and gamma positions relative to the pi carbon centers and by line width effects due to restricted rotations of the perfluoroalkyl groups around the C-C single bonds. The case of tetrakis(trifluoromethyl)ethylene has been analyzed in detail, and it is concluded that the rotation motion of the four trifluoromethyl groups should be in part correlated.
http://pubs.acs.org/doi/abs/10.1021/j100060a017
published September 14, 1993
posted in Oxyfluorides, Patents - 1993
author

Process for the Dehalogenation of 1,3-Dioxolanes

US Patent: 5245054

Date: Sep. 14, 1993

Inventors: W. Navarrini, L. Bragante

US5245054 – PDF

published August 31, 1993
posted in Patents - 1993
author

Process for Preparing Perfluoroalkoxysulphonic Compounds

US Patent: 5241110

Date: Aug. 31, 1993

Inventors: W. Navarrini, V. Montanari, A. M. Staccione

US5241110 – PDF