5,291 research outputs found
Reactions of a phosphinito bridged diplatinum(I) complex with coinage metal electrophiles
No full textWe have recently described the synthesis of the complex
[(PHCy2)Pt1(m-PCy2){k2P,O-m-P(O)Cy2}Pt2(PHCy2)] (Pt-Pt)
(1), the first unsymmetrical phosphinito bridged Pt(I) species.[1]
The phosphinito bridge differentiates the charge distributions on
the two platinum atoms as confirmed by NMR spectroscopy
(dPt(1) = -4798 ppm, dPt(2) = -5207 ppm) and DFT studies. Complex
1 shows a rich chemistry as it reacts with nucleophiles [PHCy2,
PCy3, P(S)HCy2],[2] protic species HX [P(OH)Cy2, PhSH, HF,
HCl, HBr, HI, HBF4],[3, 4] and small molecules such as H2.[5]
Recently, we started investigations on the reactivity of complex 1
towards Au and Ag based electrophiles.
In this communication, it will be shown that, differently
from the isolobal H+ (which attacks the phosphinito oxygen and
migrates onto the Pt-Pt bond),3 the [Ag(PPh3)]+ electrophile
attacks complex 1 selectively to the Pt2-mP bond to afford the
cationic cluster [(PHCy2)Pt1(m-PCy2){k2P,O-m-P(O)Cy2}Pt2{m-
-Ag(PPh3)}(PHCy2)]+ (Pt–Pt) (2+) in which the [Ag(PPh3)]+
moiety bridges the mP-Pt2 bond. Analogous reactivity is observed
also when phosphane free electrophiles such as AgOTf, AgBF4,
AgClO4 and AgCl are used. Moreover, the reactivity of 1 towards
Au(I) electrophiles such as AuCl and [Au(PPh3)Cl] was dependent
on the reagent and on the experimental conditions.
references:
1. Gallo, V.; Latronico, M.; Mastrorilli, P.; Nobile, C. F.;
Suranna, G. P.; Ciccarella, G.; Englert, U.; Eur. J. Inorg.
Chem., 2005, 4607–4616.
2. Gallo, V.; Latronico, M.; Mastrorilli, P.; Nobile, C. F.;
Polini, F.; Re, N.; Englert, U.; Inorg. Chem., 2008, 47,
4785–4795.
3. Latronico, M.; Polini, F.; Gallo, V.; Mastrorilli, P;
Calmuschi-Cula B.; Englert, U.; Re, N.; Repo T.,
Raisanen M.; Inorg. Chem., 2008, 47, 9979-9796.
4. M. Latronico, P. Mastrorilli, V. Gallo, M.M.Dell’Anna,
F. Creati, N. Re, U. Englert, Inorg. Chem. 2011, 50,
3539–3558
5. Mastrorilli P., Latronico M., Gallo V., Polini F., Re N.,
Marrone A., Gobetto R., Ellena S.. J. Am. Chem. Soc.
2010, 132, 4752–476
Contro la funzionalizzazione della contrattazione collettiva. Riflessioni sul pensiero di Mario Rusciano
No full textL'autore riflette sul pensiero di Mario Rusciano in punto di funzionalizzazione della contrattazione collettiva.The author reflects on the thought of Mario Rusciano in relation to the subject of the functionalisation of collective bargaining
Activation of small molecules by an amphiphilic phosphinito bridged Pt(I)-Pt(I) complex
No full textThe complex [(PHCy2)Pt(μ-PCy2){κ2P,O-μ-P(O)Cy2}Pt(PHCy2)](Pt-Pt) (1) constitutes a rare example of unsymmetrical phosphinito diplatinum species that, due to the simultaneous presence of a soft binding atom (P) linked to a hard one (O), undergoes smooth reaction with nucleophiles, electrophiles, dihydrogen and terminal alkynes. The tested nucleophiles were PHCy2, PCy3, P(S)HCy2 and CO, whereas the investigated electrophiles were several Brønsted acids as well as metal based species (AuCl, Au(PPh3)Cl, AgX, X = OTf, BF4, ClO4, Cl, (PPh3)OTf). The alkynes used in reaction with 1 were (trimethylsilyl)acetylene and phenylacetylene. In all cases the skeletal framework was preserved and in one case (reaction with diluted HF) dimerization led to a tetranuclear species
The reactivity of Ni(II)-tertiary phosphine complexes towards alkoxides under carbon monoxide: methoxo-carbonyl complexes, synthesis and reactivity
No full textThe reactivity of some Ni(II)-tertiary phosphine complexes, NiX2L2 (X=Cl, Br, I; L=tertiary alkylphosphine), towards the RONa (R=Me, Et, Ph, PhCH2) alkoxides under carbon monoxide, has been studied. Whereas their reactions with methoxide yield trans-NiXL2COOCH3 methoxo-carbonyl complexes, those with the other alkoxides lead to the formation of organic and inorganic products such as aldehydes, hydrocarbons, CO2 or derivatives, Ni(II) and Ni(0) compounds. This behaviour could be explained by assuming that the reactions lead to the formation of unstable NiXL2(OR) alkoxo complexes, which can either react with CO to yield the alkoxo-carbonyls NiXL2COOR, or else decompose to Ni compounds and organic products. The alkoxo complexes have not been isolated but in some cases spectroscopic evidence of their formation has been obtained. Furthermore, we have studied the reactivity of methoxo-carbonyl complexes towards amines and alkoxides: under CO they are not very reactive either in mild or in drastic conditions, and above all yield compounds which derive from decarbonylative and decarboxylative decomposition
Uncovering Intramolecular π‐Type Hydrogen Bonds in Solution by NMR Spectroscopy and DFT Calculations
No full textReaction between the phosphinito bridged diplatinum species [(PHCy2 )Pt(μ-PCy2 )κ(2) P,O-μ-P(O)Cy2 Pt(PHCy2 )](Pt-Pt) (1), and (trimethylsilyl)acetylene at 273 K affords the σ-acetylide complex [(PHCy2 )(η(1) -Me3 SiC≡C)Pt(μ-PCy2 )Pt(PHCy2 )κP-P(OH)Cy2 ](Pt-Pt) (2) featuring an intramolecular π-type hydrogen bond. Scalar and dipolar couplings involving the POH proton were detected by 2D NMR experiments. Relativistic DFT calculations of the geometry, relative energy, and NMR properties of model systems of 2 confirmed the structural assignment and allowed the energy of the π-type hydrogen bond to be estimated (ca. 22 kJ mol(-1) )
Il diritto penale nel canone di Mario Romano
No full textThis paper deals with the extension and the extraordinary scientific value of the works written by a great Master in Criminal Law, such as Mario Romano. The Author briefly presents some of the most relevant contributions given by Professor Mario Romano to the Criminal Science, first of all his "Commentario sistematico del codice penale" (Systematic Commentary on the penal code), a unique work. Finally, the paper talks about some topics which have been developed inside the work "Studi in onore di Mario Romano" (Studies in Honour of Mario Romano)
Porphodimethene–porphyrinogen relationship: the generation of unprecedented forms of porphyrinogen
No full textThe electrophilic reactivity of the porphodimethene skeleton towards nucleophiles led the establishment of a synthetic methodology to unprecedented forms of porphyrinogen containing the vinylidene substituents as well as other functionalities in the meso-position
Metodo e dispositivo di determinazione della propensione alla conservazione di uva da tavola
No full textSynthesis of Heterodimetallic Complexes by Reaction of a Terminal Phosphido Pt Complex with Metal Based Nucleophiles and Electrophiles
No full textThe complex trans-[PtCl(PCy2)(PHCy2)2] (1) possesses a terminal
phosphanido group (PCy2) and a chloride ligand,
which render it a good candidate for the synthesis of phosphanido-
bridged heterodimetallic species (PHCy2)2Pt(μ-
PCy2)M–L by reaction either with carbonyl metalates, as
metal-based nucleophiles, or with metal-based electrophiles.
The heterodinuclear complexes [(PHCy2)2Pt(μ-PCy2)Co-
(CO)3](Pt–Co) (2), [(PHCy2)2Pt(μ-PCy2)Mo(CO)2Cp](Pt–Mo)
(3), and [(PHCy2)2Pt(μ-PCy2)W(CO)2Cp](Pt–W) (4) are obtained
by reaction of 1 with the carbonyl metalates Na[Co-
(CO)4], Na[Mo(CO)3Cp] and Na[W(CO)3Cp], respectively.
Although 2 is reluctant to react with carbon monoxide, 3 and
4 are promptly carbonylated under ambient conditions to afford
mixtures of the cis and trans isomers of [(PHCy2)(CO)-
Pt(μ-PCy2)M(CO)2Cp] (M = Mo or W), which interconvert
through dissociation/reassociation of the CO ligand coordinated
to the Pt centre. The reaction of 1 with AuCl(PPh3)
leads to the formation of the trinuclear Pt2Au complexes cisand
trans-[{Cl(PHCy2)2Pt(μ-PCy2)}2Au]Cl (cis- and trans-
[8]Cl), in which a Au atom bridges two molecules of 1
through the originally terminal phosphanide ligands
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