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Palladium 0 state, complexes

A wide variety of complexes are formed by both metals in the +2 oxidation state indeed, it is the most important one for palladium. The complexes can be cationic, neutral or anionic. Both Pd2+ and Pt2+ are soft acids so that many stable complexes are formed with S or P as donor atoms but few with O-donors, though there are important ammines. There are pronounced similarities between corresponding palladium and platinum complexes the latter are more studied (and less labile). [Pg.199]

Palladium(V) complexes, 5, 1100 Palladium compounds photothermography, 6, 118 Palladium dichloride solid state oligomerization, 1, 187 Palladium(II) salts sensitizers... [Pg.190]

The studies on palladium-phosphine complexes, especially those with diphosphine ligands, have mainly been focused on the complexes of palladium in lower oxidation state of 0 and 1 84,580,581,583,766,787,788,811-816 suc]1 as [Pd2(dppm)2]2+, [Pd2(dppm)3],815 [Pd3(dppm)3(/i3-... [Pg.640]

Relatively few investigations involving palladium carbonyl clusters have been carried out, partly because palladium per se does not form stable, discrete homometallic carbonyl clusters at room temperature in either solid or solution states.114,917-922 Nevertheless, solution-phase palladium carbonyl complexes have been synthesized with other stabilizing ligands (e.g., phosphines),105,923 and carbon monoxide readily absorbs on palladium surfaces.924 Moreover, gas-phase [Pd3(CO)n]-anions (n = 1-6) have been generated and their binding energies determined via the collision-induced dissociation method.925... [Pg.648]

Olofsson-Martensson, M., U. Haussermann, J. Tomkinson, and D. Noreus, Stabilization of electron-dense palladium-hydrido complexes in solid-state hydrides, /. Am. Chem. Soc., 122, 6960,2000. [Pg.406]

Exposure of the crystalline palladium(O) complex 10 to air at room temperature caused a color change from deep red to pale yellow. The formation of the palladium(II)peroxocarbonate complex 12 was confirmed by spectroscopic analysis as well as a solid-state structure. Control reactions revealed that the first intermediate is a palladium(II)peroxo complex 11. [Pg.186]

Palladium(I) complexes are in general dimeric or oligomeric and consequently, although they have a d9 configuration, they are usually diamagnetic. The chemistry of this oxidation state is discussed in Section 51.3. Unlike most transition metals, the chemistry of low valent palladium is not dominated by carbonyls [Pd(CO)4] is only stable at 80 K in a matrix. As with platinum, the most common complexes are those containing phosphines, where complexes of the type [PdL ] (n = 2, 4) have been isolated. The chemistry of palladium(O) is dealt with in Section 51.2 and elsewhere.2... [Pg.1100]

We should review the basic chemistry of palladium, as you will be seeing many more cxampL of these steps in specialized situations. Palladium chemistry is dominated by two oxidation state The lower, palladium(O), present in tetrakis(triphenylphosphine)palladium, for example, is nom nally electron-rich, and will undergo oxidative addition with suitable substrates such as halidt and triflates (TfO- = CFsSC CT), resulting in a palladium(II) complex, Oxidative addition thought to occur on the coordinatively unsaturated 14-electron species, formed by ligand dissocia tion in solution. [Pg.1320]

Figure 22-4 Mechanism for the hydrosilylation and dehydrogenative silylation of 1-alkenes catalyzed by cationic palladium complexes Pd represents [(phen)Pd]+. The palladium alkene complex A is the resting state of the cycle. Cycle I denotes the hydrosilylation cycle, Cycle II describes the dehydrogenative silylation reaction. Figure 22-4 Mechanism for the hydrosilylation and dehydrogenative silylation of 1-alkenes catalyzed by cationic palladium complexes Pd represents [(phen)Pd]+. The palladium alkene complex A is the resting state of the cycle. Cycle I denotes the hydrosilylation cycle, Cycle II describes the dehydrogenative silylation reaction.
An important property of metal-bound phosphole ligands is their ability to undergo additional reactions not possible in the noncomplexed form. This is nicely illustrated by the thermally induced reactions of the palladium(ll) complex of 1-phenyl-3,4-dimethylphosphole 341 <1996IC1486>. Heating complex 341 at 145 °C in solution or at 140 °C in the solid state led to the formation of a mixed 7-phosphanorbornene-phosphole complex 343 (Scheme 114). These intramolecular [4-1-2] cycloaddition reactions are believed to proceed via the initial formation of a diallyl 1,4-biradical TS 342. Further examples of this type of reaction may be found in Section 3.15.12.1.1. [Pg.1128]

Higher temperatures and polar solvents are considered to switch the reaction mechanism of transmetalation from a four-centered transition state (Se2 (cyclic)) to a back-side attack of the palladium(II) complex (Se2 (open)) (Fig.1). [Pg.80]

For the palladium dibenzylideneacetone complex (1), NMR data to support the proposition that the bis-phosphine acts as a bidentate ligand has been reported. A triflate salt of the TT-allyl palladium complex has been isolated and is stable in the solid state. However, no crystals suitable for X-ray analysis were obtained. An X-ray crystal structure of the ligand and a bis-palladium complex has been reported. The palladium complexes are generated just before use under an inert atmosphere exposure to air affords a catalytically inactive tetra-coordinated palladium(II) species. ... [Pg.100]


See other pages where Palladium 0 state, complexes is mentioned: [Pg.567]    [Pg.206]    [Pg.87]    [Pg.559]    [Pg.564]    [Pg.584]    [Pg.584]    [Pg.645]    [Pg.646]    [Pg.378]    [Pg.975]    [Pg.976]    [Pg.196]    [Pg.350]    [Pg.13]    [Pg.20]    [Pg.137]    [Pg.142]    [Pg.163]    [Pg.1100]    [Pg.9]    [Pg.503]    [Pg.529]    [Pg.147]    [Pg.276]    [Pg.8]    [Pg.19]    [Pg.19]    [Pg.176]    [Pg.132]    [Pg.172]    [Pg.590]   
See also in sourсe #XX -- [ Pg.1042 ]




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