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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
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
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
Role of the Pt-O fragment in the reactivity of a phosphinito bridged diplatinum(I) complex
No full textThe role of the Pt-M bond strength in the reactivity of DPPA-like Pt(II) complexes towards metal carbonyl anions
No full text
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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) )
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