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Papers by Emanuele Amadio

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Journal of CO2 Utilization

Cosmetics

Spirulina stands out as a sustainable bioactive microalga with health-promoting properties, and a... more Spirulina stands out as a sustainable bioactive microalga with health-promoting properties, and an important active ingredient of natural cosmetics products. Currently, Spirulina has been incorporated in topical skin-care formulations, such as a moisturizing, antiwrinkles, antiaging and antiacne agent. Furthermore, this microalga is used by cosmetic formulators to promote healthy sunscreen protection, to treat skin pigmentation disorders and to heal wounds. Most of commercial cosmetics claim a large range of Spirulina properties, including antioxidant, revitalizing, remineralizing, moisturizing, protecting alongside cleansing and shining action, both for hair and for skin. In this review, recent cosmetic applications of Spirulina are revised, by highlighting its ability in improving skin appearance and health. Additionally, the analysis of the Spirulina cosmetic benchmark is discussed. Looking at the current emergence of the beauty industry, many Spirulina extracts and dry powder/fl...

ACS Applied Materials & Interfaces

The spin−spin interactions between unpaired electrons in organic (poly)radicals, especially nitro... more The spin−spin interactions between unpaired electrons in organic (poly)radicals, especially nitroxides, are largely investigated and are of crucial importance for their applications in areas such as organic magnetism, molecular charge transfer, or multiple spin labeling in structural biology. Recently, 2,2,6,6-tetramethylpiperidinyloxyl and polymers functionalized with nitroxides have been described as successful redox mediators in several electrochemical applications; however, the study of spin−spin interaction effect in such an area is absent. This communication reports the preparation of a novel family of discrete polynitroxide molecules, with the same number of radical units but different arrangements to study the effect of intramolecular spin−spin interactions on their electrochemical potential and their use as oxidation redox mediators in a Li−oxygen battery. We find that the intensity of interactions, as measured by the d 1 /d electron paramagnetic resonance parameter, progressively lowers the reduction potential. This allows us to tune the charging potential of the battery, optimizing its energy efficiency.

Journal of CO2 Utilization

Advanced Synthesis & Catalysis

Green Chemistry

We report for the first time that irradiation of four different citric acid-derived carbon dots (... more We report for the first time that irradiation of four different citric acid-derived carbon dots (CDs), in the absence of any other redox mediators, promotes an organic reaction.

Molecules

This work systematically compares both structural features and photocatalytic performance of a se... more This work systematically compares both structural features and photocatalytic performance of a series of graphitic and amorphous carbon dots (CDs) prepared in a bottom-up manner from fructose, glucose, and citric acid. We demonstrate that the carbon source and synthetic procedures diversely affect the structural and optical properties of the CDs, which in turn unpredictably influence their photo electron transfer ability. The latter was evaluated by studying the photo-reduction of methyl viologen. Overall, citric acid-CDs were found to provide the best photocatalytic performance followed by fructose- and glucose-CDs. However, while the graphitization of glucose- and citric acid-CDs favored the photo-reaction, a reverse structure–activity dependence was observed for fructose-CDs due to the formation of a large graphitic-like supramolecular assembly. This study highlights the complexity to design in advance photo-active bio-based carbon nanomaterials.

Advanced Synthesis & Catalysis

The aerobic oxidative CC bond cleavage of vicinal diols catalyzed by vanadium amino triphenolates... more The aerobic oxidative CC bond cleavage of vicinal diols catalyzed by vanadium amino triphenolates is described. Our results show that CC bond cleavage can be performed in different solvents, under an air or oxygen atmosphere, with a large variety of glycols (cyclic or linear, with aromatic or aliphatic substituents) affording the corresponding carbonyl derivatives with high chemoselectivity. Reactions can be performed with as little as 10 ppm of catalyst reaching TON up to 81,000 and TOFs of up to 4150 h-1. A reaction mechanism, rationalized by density functional theory calculations, is also proposed.

Catalysts

The reactivity of glycerol with trimethyl orthoformate is here described with an emphasis on deve... more The reactivity of glycerol with trimethyl orthoformate is here described with an emphasis on developing a reliable synthetic approach for glycerol valorization. The glycerol based orthoester 4-(dimethoxymethoxy)methyl)-2-methoxy-1,3-dioxolane (3) was synthesized, under catalytic as well as catalyst-free conditions, by taking advantage of the thermodynamically controlled equilibrium between intermediates. Both Brønsted and Lewis acid catalysts accelerated the attainment of such an equilibrium, particularly Brønsted acidic ionic liquids BSMImHSO4 and BSMImBr were the most effective compounds for this reaction. The kinetic profiles allowed the proposal of a mechanism that accounts for the selectivity of the reaction.

ACS Medicinal Chemistry Letters

ACS Sustainable Chemistry & Engineering

ACS Applied Materials & Interfaces

Inorganica Chimica Acta, 2016

* The H 2 O displaces MeOH from the carbomethoxy complex 2', with formation of a Pd-COOH + specie... more * The H 2 O displaces MeOH from the carbomethoxy complex 2', with formation of a Pd-COOH + species, which upon evolution of CO 2 gives the hydride 1 that starts the catalytic cycle which undergoes through an acyl type intermediate. After catalysis, in place of the starting complex, the acyl complex is recovered † When using Pd(II)-diphosphine based catalysts the carbonylation proceeds via both the Pd-H and Pd-COOR mechanisms even in the absence of BQ.

Catal. Sci. Technol., 2015

The best catalytic performance was exhibited by a Lewis base P∩P ligand with a relatively wide bi... more The best catalytic performance was exhibited by a Lewis base P∩P ligand with a relatively wide bite angle capable of maintaining a cis geometry.

Coordination Chemistry Reviews, 2015

Applied Catalysis A: General, 2014

The water soluble pyridyl-triazole ligand sodium 2-(1-((pyridin-2-yl)methyl)-1H-1,2,3-triazol-4-y... more The water soluble pyridyl-triazole ligand sodium 2-(1-((pyridin-2-yl)methyl)-1H-1,2,3-triazol-4-yl) ethyl sulfate (Na1) has been successfully employed in combination with ruthenium and iridium for catalytic hydrogenation of C C and C O double bonds in water/toluene biphasic systems. Reaction of the ligand with [RuCl 2 (6-p-cymene)] 2 affords the new water soluble complex [RuCl(6-p-cymene)(1)] (2) which has been found to be catalytically active in the water/organic solvent biphasic hydrogenation using styrene and 2-cyclohexen-1-one as model substrates. Very conveniently, the iridium based catalytic system is prepared by simply stirring in water [Ir(4-COD)Cl] 2 with Na1 (Ir:Na1 molar ratio = 1:4), the resulting solution is catalytically active and appears more efficient than 2. With both the Ru-and Ir-based systems the catalytically active aqueous phases can be used at least three times without loss of activity.

info:eu-repo/semantics/nonPublishe

Journal of CO2 Utilization

Cosmetics

Spirulina stands out as a sustainable bioactive microalga with health-promoting properties, and a... more Spirulina stands out as a sustainable bioactive microalga with health-promoting properties, and an important active ingredient of natural cosmetics products. Currently, Spirulina has been incorporated in topical skin-care formulations, such as a moisturizing, antiwrinkles, antiaging and antiacne agent. Furthermore, this microalga is used by cosmetic formulators to promote healthy sunscreen protection, to treat skin pigmentation disorders and to heal wounds. Most of commercial cosmetics claim a large range of Spirulina properties, including antioxidant, revitalizing, remineralizing, moisturizing, protecting alongside cleansing and shining action, both for hair and for skin. In this review, recent cosmetic applications of Spirulina are revised, by highlighting its ability in improving skin appearance and health. Additionally, the analysis of the Spirulina cosmetic benchmark is discussed. Looking at the current emergence of the beauty industry, many Spirulina extracts and dry powder/fl...

ACS Applied Materials & Interfaces

The spin−spin interactions between unpaired electrons in organic (poly)radicals, especially nitro... more The spin−spin interactions between unpaired electrons in organic (poly)radicals, especially nitroxides, are largely investigated and are of crucial importance for their applications in areas such as organic magnetism, molecular charge transfer, or multiple spin labeling in structural biology. Recently, 2,2,6,6-tetramethylpiperidinyloxyl and polymers functionalized with nitroxides have been described as successful redox mediators in several electrochemical applications; however, the study of spin−spin interaction effect in such an area is absent. This communication reports the preparation of a novel family of discrete polynitroxide molecules, with the same number of radical units but different arrangements to study the effect of intramolecular spin−spin interactions on their electrochemical potential and their use as oxidation redox mediators in a Li−oxygen battery. We find that the intensity of interactions, as measured by the d 1 /d electron paramagnetic resonance parameter, progressively lowers the reduction potential. This allows us to tune the charging potential of the battery, optimizing its energy efficiency.

Journal of CO2 Utilization

Advanced Synthesis & Catalysis

Green Chemistry

We report for the first time that irradiation of four different citric acid-derived carbon dots (... more We report for the first time that irradiation of four different citric acid-derived carbon dots (CDs), in the absence of any other redox mediators, promotes an organic reaction.

Molecules

This work systematically compares both structural features and photocatalytic performance of a se... more This work systematically compares both structural features and photocatalytic performance of a series of graphitic and amorphous carbon dots (CDs) prepared in a bottom-up manner from fructose, glucose, and citric acid. We demonstrate that the carbon source and synthetic procedures diversely affect the structural and optical properties of the CDs, which in turn unpredictably influence their photo electron transfer ability. The latter was evaluated by studying the photo-reduction of methyl viologen. Overall, citric acid-CDs were found to provide the best photocatalytic performance followed by fructose- and glucose-CDs. However, while the graphitization of glucose- and citric acid-CDs favored the photo-reaction, a reverse structure–activity dependence was observed for fructose-CDs due to the formation of a large graphitic-like supramolecular assembly. This study highlights the complexity to design in advance photo-active bio-based carbon nanomaterials.

Advanced Synthesis & Catalysis

The aerobic oxidative CC bond cleavage of vicinal diols catalyzed by vanadium amino triphenolates... more The aerobic oxidative CC bond cleavage of vicinal diols catalyzed by vanadium amino triphenolates is described. Our results show that CC bond cleavage can be performed in different solvents, under an air or oxygen atmosphere, with a large variety of glycols (cyclic or linear, with aromatic or aliphatic substituents) affording the corresponding carbonyl derivatives with high chemoselectivity. Reactions can be performed with as little as 10 ppm of catalyst reaching TON up to 81,000 and TOFs of up to 4150 h-1. A reaction mechanism, rationalized by density functional theory calculations, is also proposed.

Catalysts

The reactivity of glycerol with trimethyl orthoformate is here described with an emphasis on deve... more The reactivity of glycerol with trimethyl orthoformate is here described with an emphasis on developing a reliable synthetic approach for glycerol valorization. The glycerol based orthoester 4-(dimethoxymethoxy)methyl)-2-methoxy-1,3-dioxolane (3) was synthesized, under catalytic as well as catalyst-free conditions, by taking advantage of the thermodynamically controlled equilibrium between intermediates. Both Brønsted and Lewis acid catalysts accelerated the attainment of such an equilibrium, particularly Brønsted acidic ionic liquids BSMImHSO4 and BSMImBr were the most effective compounds for this reaction. The kinetic profiles allowed the proposal of a mechanism that accounts for the selectivity of the reaction.

ACS Medicinal Chemistry Letters

ACS Sustainable Chemistry & Engineering

ACS Applied Materials & Interfaces

Inorganica Chimica Acta, 2016

* The H 2 O displaces MeOH from the carbomethoxy complex 2', with formation of a Pd-COOH + specie... more * The H 2 O displaces MeOH from the carbomethoxy complex 2', with formation of a Pd-COOH + species, which upon evolution of CO 2 gives the hydride 1 that starts the catalytic cycle which undergoes through an acyl type intermediate. After catalysis, in place of the starting complex, the acyl complex is recovered † When using Pd(II)-diphosphine based catalysts the carbonylation proceeds via both the Pd-H and Pd-COOR mechanisms even in the absence of BQ.

Catal. Sci. Technol., 2015

The best catalytic performance was exhibited by a Lewis base P∩P ligand with a relatively wide bi... more The best catalytic performance was exhibited by a Lewis base P∩P ligand with a relatively wide bite angle capable of maintaining a cis geometry.

Coordination Chemistry Reviews, 2015

Applied Catalysis A: General, 2014

The water soluble pyridyl-triazole ligand sodium 2-(1-((pyridin-2-yl)methyl)-1H-1,2,3-triazol-4-y... more The water soluble pyridyl-triazole ligand sodium 2-(1-((pyridin-2-yl)methyl)-1H-1,2,3-triazol-4-yl) ethyl sulfate (Na1) has been successfully employed in combination with ruthenium and iridium for catalytic hydrogenation of C C and C O double bonds in water/toluene biphasic systems. Reaction of the ligand with [RuCl 2 (6-p-cymene)] 2 affords the new water soluble complex [RuCl(6-p-cymene)(1)] (2) which has been found to be catalytically active in the water/organic solvent biphasic hydrogenation using styrene and 2-cyclohexen-1-one as model substrates. Very conveniently, the iridium based catalytic system is prepared by simply stirring in water [Ir(4-COD)Cl] 2 with Na1 (Ir:Na1 molar ratio = 1:4), the resulting solution is catalytically active and appears more efficient than 2. With both the Ru-and Ir-based systems the catalytically active aqueous phases can be used at least three times without loss of activity.