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Your search keyword '"Cesarotti, Edoardo"' showing total 125 results
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125 results on '"Cesarotti, Edoardo"'

8. 2,2',5,5'-tetramethyl-4,4'-bis(diphenylphosphino)-3,3'-bithiophene: a new, very efficient, easily accessible, chiral biheteroaromatic ligand for homogeneous stereoselective catalysts

Author

Benincori, Tiziana, Cesarotti, Edoardo, Piccolo, Oreste, and Sannicolo, Franco

Subjects
Stereochemistry -- Research, Catalysis -- Analysis, Ligands (Biochemistry) -- Analysis, Transition metals -- Influence, Biological sciences, Chemistry
Abstract

Research demonstrates the synthesis of the chelating ligand enantiopure (plus)- and (minus)- 2,2',5,5'-tetramethyl-4,4'-bis(diphenylphosphino)-3,3'-bithiophene exhibiting a C(sub)2-symmetry. The electron rich metal associated diphosphine serves as catalysts in homogeneous hydrogenation of prostereogenic carbonyl functions.

Published
2000

9. On the relation between carbonyl stretching frequencies and the donor power of chelating diphosphines in nickel dicarbonyl complexes† †Electronic supplementary information (ESI) available: Antisymmetric νexpCOvs. pK a and E 0, calculated β angles, correlation between CTdon and νcalcCO, experimental 1H, 13C{1H}, 31P{1H} NMR spectra of complexes, and optimized geometries of the complexes. See DOI: 10.1039/c7cp00982h Click here for additional data file

Author

Fusè, Marco, Rimoldi, Isabella, Cesarotti, Edoardo, Rampino, Sergio, and Barone, Vincenzo

Subjects
Chemistry, education
Abstract

We unravel the mechanisms of chelation-bond formation in nickel dicarbonyl complexes with bidentate phosphines and demonstrate that σ donation drives the carbonyl stretching response to the metal–ligand bond formation., The relation between spectroscopic observables and the detailed metal–ligand bonding features in chelation complexes is addressed using both experimental and state-of-the-art theoretical and computational methods. We synthesized and characterized a set of six nickel dicarbonyl complexes of general formula [Ni(CO)2(PP)], where PP is an atropoisomeric chelating diphosphine ligand. The analysis of the obtained experimental data and the basicity and oxidative potentials of the free ligands suggests a close relation between the donor ability of the chelating ligand and the carbonyl stretching frequencies observed in the complexes. We then use theory to unravel the detailed mechanisms of chelation-bond formation in terms of partial charge flows between the molecular orbitals of the fragments. By extending the promising, recently published natural orbitals for chemical valence/charge displacement (NOCV/CD) analysis scheme we provide a thorough, quantitative description of the several charge fluxes following the metal–ligand bond formation and demonstrate that the carbonyl stretching frequencies in the considered complexes selectively respond to the σ-donation charge flow from the phosphorus lone pairs of the ligands, with the frequency shift being in quantitative correlation with the extent of the ligand-to-metal charge transfer.

Published
2017

10. New class of chiral diphosphine: ligands for highly efficient transition metal-catalyzed stereoselective reactions: the bis(diphenylphosphino) five-membered biheteroaryls

Author

Benincori, Tiziana, Brenna, Elisabetta, Sannicolo, Franco, Trimarco, Licia, Antognazza, Patrizia, Cesarotti, Edoardo, Demartin, Francesco, and Pilati, Tullio

Subjects
Ligands -- Analysis, Aromatic compounds, Organic compounds -- Analysis, Biological sciences, Chemistry
Abstract

The optically pure bis(diphenylphosphino)bibenzo[b]thiophenes tetraMe-bitianp and 4,5-demethylbenzo[b]thiophene belong to a new class of chiral ligands. The diphosphines can be utilized for asymmetric homogeneous catalysis with high enantioselectivity that is similar to binap ligands. The chiral ligands are composed of metallacycle with two interconnected five-membered units that exhibit good catalytic ability. The electronic properties of the phosphine groups and the configurational stability of the ligand depends on the type of heterocyclic system.

Published
1996

12. Luminescent water-soluble cycloplatinated complexes: Structural, photophysical, electrochemical and chiroptical properties

Author

Ionescu, Andreea, Godbert, Nicolas, Ricciardi, Loredana, La Deda, Massimo, Aiello, Iolinda, Ghedini, Mauro, Rimoldi, Isabella, Cesarotti, Edoardo, Facchetti, Giorgio, Mazzeo, Giuseppe, Longhi, Giovanna, Abbate, Sergio, Fusè, Marco, Fuse', Marco, Ionescu, Andreea, Godbert, Nicola, Ricciardi, Loredana, La Deda, Massimo, Aiello, Iolinda, Ghedini, Mauro, Rimoldi, Isabella, Cesarotti, Edoardo, Facchetti, Giorgio, Mazzeo, Giuseppe, Longhi, Giovanna, Abbate, Sergio, and Fusè, Marco

Subjects
chemistry.chemical_classification, Materials Chemistry2506 Metals and Alloys, Luminescence, 010405 organic chemistry, Chemistry, Ligand, Electronic circular dichroism, Time-dependent density functional theory, 010402 general chemistry, Photochemistry, Electrochemistry, 01 natural sciences, 0104 chemical sciences, Inorganic Chemistry, Vibrational circular dichroism, Circularly polarized luminescence, Pt(II) chiral complexe, Materials Chemistry, Structural isomer, Physical chemistry, Counterion, Physical and Theoretical Chemistry, HOMO/LUMO
Abstract

The luminescent square-planar Pt(II) complexes of the type [Pt(C^N)(N^N)] + X - , where (C^N) is the cyclometallated 2-phenylpyridine ligand, (N^N) a chiral diamine and BF 4 − or CH 3 COO − as counterion (X − ) have been synthesized. The chiral diamine Campy has been used, resulting in a mixture of regioisomers. The complexes were characterized and their structures in solution were determined by a combination of different spectroscopic and chiroptical techniques (NMR, UV–Vis, ECD, IR, VCD and CPL) associated with electrochemical, DFT and TDDFT studies. Remarkably, the acetate derivatives proved to be soluble and stable in water for at least a month. The electrochemical behaviour of the [Pt(C^N)(N^N)]BF 4 was investigated and the LUMO energies estimated. The photophysical properties of the new compounds were deeply investigated in water or dimethyl sulfoxide solution by UV–Vis, steady state emission and time-correlated single-photon counting spectroscopy.

Published
2017

13. Mono- and dinuclear complexes of platinum(II) with chiral diphosphines: Pt(P-P')Cl2 and (Pt P-P' mu-OH)2(BF4)2: P-P' = prolophos, N-(diphenylphosphino)-2-(diphenylphosphinoxy-methyl)pyrrolidine, and butaphos, 1-(diphenylphosphinoxy)-2-(N-ethyl-N-diphenylphosphino-amino)butane: crystal and molecular structure of Pt(S-prolophos-P,P')Cl2

Author

Bandini, Anna Laura, Banditelli, Guido, Cesarotti, Edoardo, Minghetti, Giovanni, and Bovio, Bruna

Subjects
Coordination compounds -- Analysis, Organometallic compounds -- Research, Gases -- Analysis, Chemistry
Abstract

The chiral complexes Pt(II) S-prolophos and Pt(II) R-butaphos result when the appropriate phosphine is stirred into a chloroform suspension of Pt(COD)Cl2. X-ray studies reveal the S-prolophos complex as orthorhombic C29H29Cl2NOP2Pt, with the diphosphine ligand bound inwardly to the Pt atom at two points in a twisted square plane and the seven-membered ring in a twisted-boat form. In the presence of tin(II) chloride, the complex catalyzes the hydroformylation of styrene to (R)-(-)-2-phenylpropanal. Treatment of the two complexes with silver tetrafluoroborate yields the corresponding dinuclear complexes useful in the synthesis of polynuclear hydrides.

Published
1992

15. Vibrational circular dichroism and chiroptical properties of chiral Ir(iii) luminescent complexes

Author

Mazzeo, Giuseppe, Fusè, Marco, Longhi, Giovanna, Rimoldi, Isabella, Cesarotti, Edoardo, Crispini, Alessandra, Abbate, Sergio, Fuse', Marco, Mazzeo, Giuseppe, Fusè, Marco, Longhi, Giovanna, Rimoldi, Isabella, Cesarotti, Edoardo, Crispini, Alessandra, and Abbate, Sergio

Subjects
Circular dichroism, 010405 organic chemistry, chemistry.chemical_element, Ionic bonding, 010402 general chemistry, Photochemistry, 01 natural sciences, 0104 chemical sciences, Inorganic Chemistry, Crystallography, chemistry, Vibrational circular dichroism, Density functional theory, Iridium, Luminescence, Chirality (chemistry), Single crystal
Abstract

The octahedral ionic Ir(iii) complex with a dual stereogenic centre of general formula Δ,Λ-(R,S)-[(ppy)2Ir(Me-Campy)]X, where ppy = 2-phenylpyridine and Me-Campy = 2-methyl-5,6,7,8-tetrahydroquinolin-8-amine, and the complex Λ-(R,S)-[(ppy)2Ir(H-Campy)]X, where ppy = 2-phenylpyridine, H-Campy = 8-amino-5,6,7,8-tetrahydroquinolines and X(-) = Cl(-) as a counterion in both cases, have been characterized by vibrational circular dichroism (VCD), which turns out to be efficacious in diastereomeric discrimination. Moreover, the single crystal X-ray structure of the complex Δ-(R)-[(ppy)2Ir(Me-Campy)]Cl is reported here. Density functional theory (DFT) calculations allow us to conclude that the most important doublet feature in the VCD spectra is associated with a clear vibrational exciton structure located on the two dissymmetrically disposed phenylpyridine ligands. The features in the VCD spectra associated with the (R) or (S)-central chirality configuration are identified and commented on. DFT calculations provide also the interpretation of electronic circular dichroism (ECD) spectra. Finally, circularly polarized luminescence (CPL) spectra are presented as an additional chiroptical characterization of these luminescent iridium complexes.

Published
2016

16. VCD spectroscopy as an excellent probe of chiral metal complexes containing a carbon monoxide vibrational chromophore

Author

Fusè, Marco, Mazzeo, Giuseppe, Longhi, Giovanna, Abbate, Sergio, Zerla, Daniele, Rimoldi, Isabella, Contini, Alessandro, Cesarotti, Edoardo, Fuse', Marco, Fusè, Marco, Mazzeo, Giuseppe, Longhi, Giovanna, Abbate, Sergio, Zerla, Daniele, Rimoldi, Isabella, Contini, Alessandro, and Cesarotti, Edoardo

Subjects
Materials Chemistry2506 Metals and Alloys, Surfaces, Coatings and Film, Ceramics and Composite, Photochemistry, Catalysis, Catalysi, Metal, chemistry.chemical_compound, Cyclopentadienyl complex, Materials Chemistry, Spectroscopy, Electronic, Optical and Magnetic Material, Chemistry (all), Metals and Alloys, General Chemistry, Chromophore, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, chemistry, visual_art, Vibrational circular dichroism, Ceramics and Composites, visual_art.visual_art_medium, Chirality (chemistry), Carbon monoxide
Abstract

Vibrational circular dichroism, VCD, gives evidence that the carbon monoxide chromophore in a heteroleptic cyclopentadienyl Ru(II)-carbonyl complex is very sensitive to the chirality of the metal centre and becomes an excellent probe to define the configuration of chiral metal complexes.

Published
2015

17. Luminescent water-soluble cycloplatinated complexes: Structural, photophysical, electrochemical and chiroptical properties

Author

Ionescu, Andreea, primary, Godbert, Nicolas, additional, Ricciardi, Loredana, additional, La Deda, Massimo, additional, Aiello, Iolinda, additional, Ghedini, Mauro, additional, Rimoldi, Isabella, additional, Cesarotti, Edoardo, additional, Facchetti, Giorgio, additional, Mazzeo, Giuseppe, additional, Longhi, Giovanna, additional, Abbate, Sergio, additional, and Fusè, Marco, additional

Published
2017
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36. Mono- and dinuclear complexes of platinum(II) with chiral diphosphines: Pt(P-P')Cl2 and [Pt(P-P')(.mu.-OH)]2[BF4]2(P-P' = prolophos, N-(diphenylphosphino)-2-((diphenylphoshpinoxy)methyl)pyrrolidine, and butaphos, 1-(diphenylphosphinoxy)-2-(N-ethyl-N-(diphenylphosphino)amino)butane). Crystal and molecular structure of P{S-prolophos-P,P'}Cl2

Author

Bandini, Anna Laura, primary, Banditelli, Guido, additional, Cesarotti, Edoardo, additional, Minghetti, Giovanni, additional, and Bovio, Bruna, additional

Published
1992
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37. 'In situ' Activation of Racemic RuII Complexes: Separation of trans and cis Species and Their Application in Asymmetric Reduction.

Author

Facchetti, Giorgio, Cesarotti, Edoardo, Pellizzoni, Michela, Zerla, Daniele, and Rimoldi, Isabella

Subjects
*HOMOGENEOUS catalysis, *RUTHENIUM, *PHOSPHINES, *LIGANDS (Chemistry), *COMPLEX compounds
Abstract

Ruthenium(II) dichlorides with racemic atropos-biaryl-based diphosphanes and optically active 1,2-diphenylethane-1,2-diamine (DPEN) as ligands have been synthesised. trans and cis isomers were formed due to the low basicity of the diphosphane ligands, in particular, with BITIANP and BIMIP. The trans and cis species were easily separated by filtration. In particular, when rac-BITIANP was used in combination with chiral DPEN, the asymmetric separation of optically pure complexes in cis and trans arrangements was realised and they were used as precatalysts in the asymmetric hydrogenation of ketones. Matching and mismatching combinations exhibited different performances. [ABSTRACT FROM AUTHOR]

Published
2012
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