6 results on '"Vaghi L."'
Search Results
2. Mechanochemical oxidation of fluorinated anilines to symmetric azobenzenes
- Author
-
Luca Vaghi, Ivan Andreosso, Antonio Papagni, Andreosso, I, Papagni, A, and Vaghi, L
- Subjects
Calcium hypochlorite ,010405 organic chemistry ,Chemistry ,Fluorinated aniline ,Organic Chemistry ,Fluorinated azobenzenes, Mechanochemistry, Oxidation, Fluorinated anilines, Phenyliodine(III)diacetate, Calcium hypochlorite ,010402 general chemistry ,Fluorinated azobenzene ,01 natural sciences ,Biochemistry ,Combinatorial chemistry ,0104 chemical sciences ,Inorganic Chemistry ,Metal ,chemistry.chemical_compound ,Reagent ,Mechanochemistry ,visual_art ,Oxidation ,visual_art.visual_art_medium ,Environmental Chemistry ,Physical and Theoretical Chemistry ,Phenyliodine(III)diacetate - Abstract
A solventless mechanochemical methodology for the oxidation of electron-poor fluorinated anilines to the corresponding symmetrical azo compounds has been developed. In this process phenyliodine(III)diacetate and inexpensive calcium hypochlorite demonstrate to be good oxidants, providing the desired fluorinated azobenzenes in satisfactory yields, within short reaction times and avoiding the use of environmental unfriendly metal reagents.
- Published
- 2018
3. Synthesis of corrugated C-based nanostructures by Br-corannulene oligomerization
- Author
-
Smerieri, Marco, Pís, Igor, Ferrighi, Lara, Nappini, Silvia, Lusuan, Angelique, Vattuone, Luca, Vaghi, Luca, Papagni, Antonio, Magnano, Elena, Di Valentin, Cristiana, Bondino, Federica, Savio, Letizia, Smerieri, M, Píš, I, Ferrighi, L, Nappini, S, Lusuan, A, Vattuone, L, Vaghi, L, Papagni, A, Magnano, E, Di Valentin, C, Bondino, F, and Savio, L
- Subjects
corrugated ,Nanostructure ,Materials science ,General Physics and Astronomy ,02 engineering and technology ,010402 general chemistry ,DBP ,01 natural sciences ,oligomerization ,law.invention ,chemistry.chemical_compound ,law ,Molecule ,Physical and Theoretical Chemistry ,C-based nanostructures ,metal surface assisted synthesis, C-based nanostructures, corannulene, Ag(110), scanning tunneling microscopy, soft X-ray spectroscopy, density functional theory ,chemistry.chemical_classification ,Polymer ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Crystallography ,Polymerization ,chemistry ,Corannulene ,Network covalent bonding ,Density functional theory ,Br-corannulene ,Scanning tunneling microscope ,0210 nano-technology - Abstract
The structure and electronic properties of carbon-based nanostructures obtained by metal surface assisted synthesis is highly dependent on the nature of the precursor molecule. Here, we report on a combined scanning tunneling microscopy, soft X-ray spectroscopy and density functional theory investigation on the surface assisted polymerization of Br-corannulene at Ag(110) and on the possibility of building a mesh of ?-conjugated polymers starting from buckyball shaped molecules. Indeed, the corannulene units form one-molecule-wide ribbons in which the natural concavity of the precursor molecule is maintained. These C-based nanostructures are corrugated and merge into a covalent network on the surface.
- Published
- 2018
4. Surface perfluoroalkyl chains segregation : a tool for reducing calcium deposits in medical grade poly(methyl methacrylate)
- Author
-
Luca Vaghi, Peter J. S. Foot, Ravtej S. Thatti, Stephen Barton, Baljit Ghatora, Antonio Papagni, Ghatora, B, Foot, P, Barton, S, Thatti, R, Papagni, A, and Vaghi, L
- Subjects
Materials science ,Scanning electron microscope ,02 engineering and technology ,010402 general chemistry ,chemistry ,01 natural sciences ,chemistry.chemical_compound ,CHIM/06 - CHIMICA ORGANICA ,Polymer chemistry ,Thin film ,Methyl methacrylate ,chemistry.chemical_classification ,metallurgy ,Poly(Methyl Methacrylate) (PMMA), Perfluoroalkyl, Segregation, Medical Polymers, Wettability, Calcium Deposits ,Polymer ,021001 nanoscience & nanotechnology ,Casting ,Poly(methyl methacrylate) ,0104 chemical sciences ,Chemical engineering ,visual_art ,visual_art.visual_art_medium ,Surface modification ,Wetting ,0210 nano-technology - Abstract
Intraocular lenses can be manufactured from a wide variety of polymers, but due to the lost cost associated with the use of Poly(methyl methacrylate) (PMMA), it is still the preferred material used in the developing countries. However, a major drawback to its use is the build-up of calcium containing deposits that are formed on the intraocular lens over a period of time. In an attempt to hinder this deposition, surface modification of medical grade PMMA has been carried out using perfluoroalkyl chain (1,2,4-trifluoro-3- (C10F21CH2O)-7-(N,N)-dimethylaminoacridine) segregation. The segregation was explored using a 1% 1,2,4-trifluoro-3-(C10F21CH2O)-7-(N,N)-dimethyla- minoacridine in two methods: film casting and spin-coating, a thin film onto preformed PMMA discs. Both methods were compared against control PMMA to determine which method provided the best hindrance against calcium containing deposits when immersed in a simulated aqueous humour solution. Characterisation of the surface using scanning electron microscopy coupled with energy; dispersive x-ray analysis indicated that the surface segregation of perfluoroalkyl chains had hindered calcification in both methods. This pleminary research shows promising results of employing perfluoroalkyl chains in the surface segregation of biomaterials that can be employed in intraocular lenses.
- Published
- 2017
5. Surface-Confined Polymerization of Halogenated Polyacenes: The Case of Dibromotetracene on Ag(110)
- Author
-
Antonio Papagni, Francesco Sedona, Lara Ferrighi, Elena Magnano, Andrea Basagni, Luca Vaghi, Stefano Agnoli, Cristiana Di Valentin, Thanh Hai Nguyen, Igor Píš, Silvia Nappini, Federica Bondino, Píš, I, Ferrighi, L, Nguyen, T, Nappini, S, Vaghi, L, Basagni, A, Magnano, E, Papagni, A, Sedona, F, DI VALENTIN, C, Agnoli, S, and Bondino, F
- Subjects
Absorption spectroscopy ,Photoemission spectroscopy ,Ag(110) ,Surfaces, Coatings and Film ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,law.invention ,dibromotetracene ,NEXAFS ,X-ray photoelectron spectroscopy ,Computational chemistry ,law ,synchrotron ,Molecule ,Physical and Theoretical Chemistry ,BACH ,Chemistry ,Electronic, Optical and Magnetic Material ,graphene ,halogenated polyacene ,021001 nanoscience & nanotechnology ,XANES ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Crystallography ,General Energy ,Energy (all) ,Polymerization ,Density functional theory ,Scanning tunneling microscope ,0210 nano-technology ,photoemission - Abstract
On-surface synthesis of thin organic and organometallic films in a bottom-up fashion has become a promising approach for the development of new nanotechnologies. In this work we studied 5,11-dibromotetracene (C18H10Br2) as a prototypical case of rodlike polyaromatic molecules functionalized with two bromine atoms on the sides. The adsorption and temperature-stimulated transformations of dibromotetracene assemblies on Ag(110) have been investigated by a combination of synchrotron radiation X-ray photoemission spectroscopy (XPS), near-edge X-ray absorption spectroscopy (NEXAFS), scanning tunneling microscopy (STM), and density functional theory (DFT) calculations. Upon the contact with the Ag substrate, the Br-C bonds are promptly cleaved at room temperature, and Ag-coordinated protopolymers are formed along the [001] substrate direction. The organometallic diners and trimers remain on the surface up to 523 K. The stabilization of the protopolymers is driven by the substrate anisotropy and weak interactions with nearby Br atoms. The short oligomers formed at elevated temperatures are weakly bounded to the substrate and desorb before covalent structures can be formed.
- Published
- 2016
6. Synthesis of graphene nanoribbons with a defined mixed edge-site sequence by surface assisted polymerization of (1,6)-dibromopyrene on Ag(110)
- Author
-
Silvia Nappini, Angelique Lusuan, Stefano Agnoli, Luca Vaghi, Antonio Papagni, Igor Píš, Mattia Cattelan, Cristiana Di Valentin, Lara Ferrighi, Marco Smerieri, Letizia Savio, Federica Bondino, Elena Magnano, Smerieri, M, Píš, I, Ferrighi, L, Nappini, S, Lusuan, A, DI VALENTIN, C, Vaghi, L, Papagni, A, Cattelan, M, Agnoli, S, Magnano, E, Bondino, F, and Savio, L
- Subjects
Coupling ,Nanostructure ,Materials science ,Graphene nanoribbons ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,law.invention ,chemistry.chemical_compound ,Polymerization ,chemistry ,surface assisted polymeriziation ,Chemical physics ,law ,Pyrene ,General Materials Science ,Density functional theory ,Dehydrogenation ,Materials Science (all) ,Scanning tunneling microscope ,0210 nano-technology - Abstract
By a combination of scanning tunneling microscopy, X-ray spectroscopic techniques and density functional theory calculations, we prove the formation of extended patterns of parallel, graphene nanoribbons with alternate zig-zag and armchair edges and selected width by surface-assisted Ullmann coupling polymerization and dehydrogenation of 1,6-dibromopyrene (C16H8Br2). Besides the relevance of these nanostructures for their possible application in nanodevices, we demonstrate the peculiarity of halogenated pyrene derivatives for the formation of nanoribbons, in particular on Ag(110). These results open the possibility of tuning the shape and dimension of nanoribbons (and hence the correlated electronic properties) by choosing suitably tailored or on-purpose designed molecular precursors.
- Published
- 2016
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.