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Papers by Sandro Campestrini

Research paper thumbnail of Stable compositions containing persulfate salts

Research paper thumbnail of ChemInform Abstract: Peroxo Complexes of Transition Metals in the Oxidation of Organic Substrates: Examples of Selectivity

Research paper thumbnail of A process for forming a peracid and a composition comprising said peracid

Research paper thumbnail of Process for the production of aldehyde or ketone compounds and aldehydes and ketones obtained by means of this process

Research paper thumbnail of The use of an aliphatic-aromatic diacyl peroxide in a bleaching composition

Research paper thumbnail of Process for the preparation of aldehydic or ketonic compounds, and aldehydes and ketones obtained by this process

Research paper thumbnail of Ossidazione di solfossidi a solfoni con H2O2 in presenza di derivati di Mo (VI); studio preliminare del meccanismo

Research paper thumbnail of Process for manufacturing aqueous compositions comprising peracids

Research paper thumbnail of Stable compositions with persulfate salts

Research paper thumbnail of Porphyrin-antimicrobial peptide conjugates: synthesis, conformational studies and preliminary light activated biocidal activity

Research paper thumbnail of Synthesis and X-Ray Crystal Structure of the First Pure and Air-Stable Salt of Peroxymonosulphuric Acid: (Ph)4PHSO5

Molecules, 2000

In this paper we describe the synthesis of tetraphenylphosphonium peroxymonosulphate, its crystal... more In this paper we describe the synthesis of tetraphenylphosphonium peroxymonosulphate, its crystal structure and packing mode. The asymmetric unit accomodates two independent molecules of the monopersulphate anion, which are held together by hydrogen bonds. In the packing mode, rows of such dimers are surrounded by four rows of tetraphenyl cations. The consequence is that the highly water sensitive HSO 5¯ anions are segregated inside hydrophobic channels composed by the lipophilic cations. This circumstance presumably accounts for the exceptional stability of the title compound.

Research paper thumbnail of Metal catalysis in oxidation by peroxides. 30. Electrophilic oxygen transfer from anionic, coordinatively saturated molybdenum peroxo complexes

The Journal of Organic Chemistry, 1988

Two anionic and coordinatively saturated oxodiperoxomolybdenum complexes, [MOO(Oz)zL]-Bu4N+ (L = ... more Two anionic and coordinatively saturated oxodiperoxomolybdenum complexes, [MOO(Oz)zL]-Bu4N+ (L = C5H4NCOZor C5H4N(O)COZ-), have been used as oxidants for a series of organic sulfides and sulfoxides in DCE. Quantitative yields of sulfoxides and sulfones, respectively, have been obtained. Spectroscopic ('H and 13C NMR) and kinetic evidence rule out any coordination process between the substrate and the oxidant requiring the formation of an unsaturated site on the metal. The data collected point to an oxidation mechanism involving a bimolecular reaction. This, at least for sulfide oxidations, appears to proceed through an electrophilic oxygen transfer from the peroxo complex to the substrate.

Research paper thumbnail of Olefin epoxidation and alkane hydroxylation catalyzed by robust sulfonated manganese and iron porphyrins supported on cationic ion-exchange resins

Inorganic Chemistry, 1992

... ClIzTMPH2) (see Chart I1 for structures of used sulfonated metalloporphyrins).Cyclooctene Epo... more ... ClIzTMPH2) (see Chart I1 for structures of used sulfonated metalloporphyrins).Cyclooctene Epoxidation Catalyzed by Supported Sulfonated MeWloporphyrhs. We first investigated the possible use of the tetra-n-butylammonium ...

Research paper thumbnail of Sustainable Epoxidation of Electron-Poor Olefins with Hydrogen Peroxide in Ionic Liquids and Recovery of the Products with Supercritical CO2

European Journal of Organic Chemistry, 2003

Epoxidation Epoxidation O 0218 Sustainable Epoxidation of Electron-Poor Olefins with Hydrogen Per... more Epoxidation Epoxidation O 0218 Sustainable Epoxidation of Electron-Poor Olefins with Hydrogen Peroxide in Ionic Liquids and Recovery of the Products with Supercritical CO 2 .-Epoxidation of electron-poor olefins is accomplished using an aqueous basic solution of hydrogen peroxide in different ionic liquids. Addition of small amounts of water results in an increase of epoxidation rate and reproducibility. Supercritical CO2 provides an almost quantitative extraction of resulting epoxides. The ionic liquids can be recovered and reused in subsequent cycles.

Research paper thumbnail of Pd-Au and Pd-Pt catalysts for the direct synthesis of hydrogen peroxide in absence of selectivity enhancers

Applied Catalysis A: General, 2013

ABSTRACT Organic polymers are suitable candidates as catalytic materials for the direct synthesis... more ABSTRACT Organic polymers are suitable candidates as catalytic materials for the direct synthesis of hydrogen peroxide (DSR) from dihydrogen and dioxygen, in view of the low temperature applied. In particular, strongly acidic ion-exchange resins have been already proposed for this reaction, either as carriers of PdII ions or Pd0 nanoparticles, but not for bimetallic Pd/Pt and Pd/Au catalysts, which are also active in this reaction. The introduction of PdII, PtII and AuIII precursors into the commercial ion-exchangers Lewatit K2621 and their subsequent reduction with an aqueous formaldehyde solution produced a library of bimetallic catalysts with 1% Pd (w/w) and a variable content of either Pt (0.1–1%, w/w) or Au (0.25–1%, w/w). The catalysts were tested with no selectivity enhancer in the DSR under batchwise condition at 2 °C in MeOH at 2 MPa, with a CO2/O2/H2 (72/25.5/2.5) mixture.

Research paper thumbnail of Catalytic Olefin Epoxidation With H2O2 in Supercritical CO2. Synergic Effect by Hexafluoroacetone and Manganese-Porphyrins

Advanced Synthesis & Catalysis, 2001

Research paper thumbnail of Stable strongly acidic aqueous compositions containing persulfate salts

Research paper thumbnail of Anhydrous Compositions Comprising a Peracid

Research paper thumbnail of Oxygen transfer from Ph4PHSO5 to manganese porphyrins: kinetics and mechanism of the formation of the oxo species in homogeneous solution

Journal of the Chemical Society, Perkin Transactions 2, 1994

ABSTRACT The kinetics and mechanism of the oxygenation of Mn(TMP)Cl, Mn(TDCPP)Cl and Mn(Br8TMP)Cl... more ABSTRACT The kinetics and mechanism of the oxygenation of Mn(TMP)Cl, Mn(TDCPP)Cl and Mn(Br8TMP)Cl by Ph4PhSO5 has been investigated in 1,2-dichloroethane and acetonitrile. In both solvents the reaction takes place only in the presence of species acting as axial ligands of the manganese porphyrins, e.g. imidazole or 4-tert-butylpyridine whose association constants to the metal have been measured. The rates of disappearance of the manganese porphyrin and of the appearance of the oxo-species, obtained by the stopped-flow technique, are identical within the experimental error. This finding, together with the determination of the kinetic law of the reaction allows us to suggest that the oxygen transfer process may be a simple bimolecular reaction or that, if an intermediate is formed, it is rather short lived.

Research paper thumbnail of Baeyer-Villiger oxidation of ketones by peroxomolybdenum complexes: A revisit

Journal of Molecular Catalysis, 1993

The Baeyer-Villiger oxidation of cyclopentanone to 8-valerolactone by a peroxomolybdenum complex,... more The Baeyer-Villiger oxidation of cyclopentanone to 8-valerolactone by a peroxomolybdenum complex, MOO (0) 2 (dipic), under catalytic (hydrogen peroxide) conditions was reported in the literature some years ago. Such a reaction might have both synthetic and mechanistic significance, being the only available example of nucleophilic reactivity of Group VI peroxometal complexes. However, the results of a reinvestigation of the reaction presented in this paper indicate that the oxidation is carried out by hydrogen peroxide and that the role of MOO (0) 2 (dipic) as well that of other molybdenum derivatives is simply to catalyze the reaction owing to their strong acid nature.

Research paper thumbnail of Stable compositions containing persulfate salts

Research paper thumbnail of ChemInform Abstract: Peroxo Complexes of Transition Metals in the Oxidation of Organic Substrates: Examples of Selectivity

Research paper thumbnail of A process for forming a peracid and a composition comprising said peracid

Research paper thumbnail of Process for the production of aldehyde or ketone compounds and aldehydes and ketones obtained by means of this process

Research paper thumbnail of The use of an aliphatic-aromatic diacyl peroxide in a bleaching composition

Research paper thumbnail of Process for the preparation of aldehydic or ketonic compounds, and aldehydes and ketones obtained by this process

Research paper thumbnail of Ossidazione di solfossidi a solfoni con H2O2 in presenza di derivati di Mo (VI); studio preliminare del meccanismo

Research paper thumbnail of Process for manufacturing aqueous compositions comprising peracids

Research paper thumbnail of Stable compositions with persulfate salts

Research paper thumbnail of Porphyrin-antimicrobial peptide conjugates: synthesis, conformational studies and preliminary light activated biocidal activity

Research paper thumbnail of Synthesis and X-Ray Crystal Structure of the First Pure and Air-Stable Salt of Peroxymonosulphuric Acid: (Ph)4PHSO5

Molecules, 2000

In this paper we describe the synthesis of tetraphenylphosphonium peroxymonosulphate, its crystal... more In this paper we describe the synthesis of tetraphenylphosphonium peroxymonosulphate, its crystal structure and packing mode. The asymmetric unit accomodates two independent molecules of the monopersulphate anion, which are held together by hydrogen bonds. In the packing mode, rows of such dimers are surrounded by four rows of tetraphenyl cations. The consequence is that the highly water sensitive HSO 5¯ anions are segregated inside hydrophobic channels composed by the lipophilic cations. This circumstance presumably accounts for the exceptional stability of the title compound.

Research paper thumbnail of Metal catalysis in oxidation by peroxides. 30. Electrophilic oxygen transfer from anionic, coordinatively saturated molybdenum peroxo complexes

The Journal of Organic Chemistry, 1988

Two anionic and coordinatively saturated oxodiperoxomolybdenum complexes, [MOO(Oz)zL]-Bu4N+ (L = ... more Two anionic and coordinatively saturated oxodiperoxomolybdenum complexes, [MOO(Oz)zL]-Bu4N+ (L = C5H4NCOZor C5H4N(O)COZ-), have been used as oxidants for a series of organic sulfides and sulfoxides in DCE. Quantitative yields of sulfoxides and sulfones, respectively, have been obtained. Spectroscopic ('H and 13C NMR) and kinetic evidence rule out any coordination process between the substrate and the oxidant requiring the formation of an unsaturated site on the metal. The data collected point to an oxidation mechanism involving a bimolecular reaction. This, at least for sulfide oxidations, appears to proceed through an electrophilic oxygen transfer from the peroxo complex to the substrate.

Research paper thumbnail of Olefin epoxidation and alkane hydroxylation catalyzed by robust sulfonated manganese and iron porphyrins supported on cationic ion-exchange resins

Inorganic Chemistry, 1992

... ClIzTMPH2) (see Chart I1 for structures of used sulfonated metalloporphyrins).Cyclooctene Epo... more ... ClIzTMPH2) (see Chart I1 for structures of used sulfonated metalloporphyrins).Cyclooctene Epoxidation Catalyzed by Supported Sulfonated MeWloporphyrhs. We first investigated the possible use of the tetra-n-butylammonium ...

Research paper thumbnail of Sustainable Epoxidation of Electron-Poor Olefins with Hydrogen Peroxide in Ionic Liquids and Recovery of the Products with Supercritical CO2

European Journal of Organic Chemistry, 2003

Epoxidation Epoxidation O 0218 Sustainable Epoxidation of Electron-Poor Olefins with Hydrogen Per... more Epoxidation Epoxidation O 0218 Sustainable Epoxidation of Electron-Poor Olefins with Hydrogen Peroxide in Ionic Liquids and Recovery of the Products with Supercritical CO 2 .-Epoxidation of electron-poor olefins is accomplished using an aqueous basic solution of hydrogen peroxide in different ionic liquids. Addition of small amounts of water results in an increase of epoxidation rate and reproducibility. Supercritical CO2 provides an almost quantitative extraction of resulting epoxides. The ionic liquids can be recovered and reused in subsequent cycles.

Research paper thumbnail of Pd-Au and Pd-Pt catalysts for the direct synthesis of hydrogen peroxide in absence of selectivity enhancers

Applied Catalysis A: General, 2013

ABSTRACT Organic polymers are suitable candidates as catalytic materials for the direct synthesis... more ABSTRACT Organic polymers are suitable candidates as catalytic materials for the direct synthesis of hydrogen peroxide (DSR) from dihydrogen and dioxygen, in view of the low temperature applied. In particular, strongly acidic ion-exchange resins have been already proposed for this reaction, either as carriers of PdII ions or Pd0 nanoparticles, but not for bimetallic Pd/Pt and Pd/Au catalysts, which are also active in this reaction. The introduction of PdII, PtII and AuIII precursors into the commercial ion-exchangers Lewatit K2621 and their subsequent reduction with an aqueous formaldehyde solution produced a library of bimetallic catalysts with 1% Pd (w/w) and a variable content of either Pt (0.1–1%, w/w) or Au (0.25–1%, w/w). The catalysts were tested with no selectivity enhancer in the DSR under batchwise condition at 2 °C in MeOH at 2 MPa, with a CO2/O2/H2 (72/25.5/2.5) mixture.

Research paper thumbnail of Catalytic Olefin Epoxidation With H2O2 in Supercritical CO2. Synergic Effect by Hexafluoroacetone and Manganese-Porphyrins

Advanced Synthesis & Catalysis, 2001

Research paper thumbnail of Stable strongly acidic aqueous compositions containing persulfate salts

Research paper thumbnail of Anhydrous Compositions Comprising a Peracid

Research paper thumbnail of Oxygen transfer from Ph4PHSO5 to manganese porphyrins: kinetics and mechanism of the formation of the oxo species in homogeneous solution

Journal of the Chemical Society, Perkin Transactions 2, 1994

ABSTRACT The kinetics and mechanism of the oxygenation of Mn(TMP)Cl, Mn(TDCPP)Cl and Mn(Br8TMP)Cl... more ABSTRACT The kinetics and mechanism of the oxygenation of Mn(TMP)Cl, Mn(TDCPP)Cl and Mn(Br8TMP)Cl by Ph4PhSO5 has been investigated in 1,2-dichloroethane and acetonitrile. In both solvents the reaction takes place only in the presence of species acting as axial ligands of the manganese porphyrins, e.g. imidazole or 4-tert-butylpyridine whose association constants to the metal have been measured. The rates of disappearance of the manganese porphyrin and of the appearance of the oxo-species, obtained by the stopped-flow technique, are identical within the experimental error. This finding, together with the determination of the kinetic law of the reaction allows us to suggest that the oxygen transfer process may be a simple bimolecular reaction or that, if an intermediate is formed, it is rather short lived.

Research paper thumbnail of Baeyer-Villiger oxidation of ketones by peroxomolybdenum complexes: A revisit

Journal of Molecular Catalysis, 1993

The Baeyer-Villiger oxidation of cyclopentanone to 8-valerolactone by a peroxomolybdenum complex,... more The Baeyer-Villiger oxidation of cyclopentanone to 8-valerolactone by a peroxomolybdenum complex, MOO (0) 2 (dipic), under catalytic (hydrogen peroxide) conditions was reported in the literature some years ago. Such a reaction might have both synthetic and mechanistic significance, being the only available example of nucleophilic reactivity of Group VI peroxometal complexes. However, the results of a reinvestigation of the reaction presented in this paper indicate that the oxidation is carried out by hydrogen peroxide and that the role of MOO (0) 2 (dipic) as well that of other molybdenum derivatives is simply to catalyze the reaction owing to their strong acid nature.