Photoelectron spectroscopy of coordination compounds. III. Comparison of platinum(II) and platinum(IV) compounds

Moddeman, W. E.; Blackburn, J. R.; Kumar, G.; Morgan, K. A.; Albridge, R. G.; Jones, Matthew M.

doi:10.1021/ic50113a056

Cited by 40 publications

(21 citation statements)

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“…In the case of positive oxidation states of platinum, a shift of approximately 1.2 eV per step is observed. [18,19,20] However, a series of new binary platinum compounds Cs 2 Pt, [21] BaPt, [22] Ba 3 Pt 2 [23] and Ba 2 Pt [24] exhibit platinum in a negative oxidation state, and in these Ba-Pt compounds, a shift of the 4f 7/2 band to smaller energy values was in fact measured; [25] this shift correlates well with the calculated AIM atomic charges (Figure 1). Yet the actual oxidation states of the elements in these compounds are not at all intuitive; only a precise analysis of the bands at the Fermi surface (e.g.…”

Section: Quantum Mechanical Descriptions Of Chemical Systems and Theisupporting

confidence: 64%

A Piece of the Picture—Misunderstanding of Chemical Concepts

2008

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Chemical concepts and quantum mechanics: Heuristic concepts are indispensable tools to give the almost boundless body of knowledge in chemistry an ordered structure and to present it didactically. Many of these concepts were developed without a full understanding of their physical backgrounds. Pulling together results from quantum chemical calculations and conceptual quantities is not always straightforward and requires close consideration of the definition of the quantity in question.

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Section: Quantum Mechanical Descriptions Of Chemical Systems and Theisupporting

confidence: 64%

A Piece of the Picture—Misunderstanding of Chemical Concepts

2008

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“…The XP spectrum of the product of oxidation of 1 with AgBF 4 showed a typical doublet with the Pt 4f 7/2 peak at 73.6 eV, consistent with the presence of platinum(III) (for this series of compounds), but this overlapped a second doublet with a 4f 7/2 peak at 71.4 eV, possibly because of metallic platinum displaced by the AgBF 4 (literature value 71.3 eV). [51][52][53][54] Electrochemical Reduction of the Axially Substituted Diplatinum(III) Complexes [Pt 2 (µ-pop) 4 X 2 ] 4-. Voltammetric Studies.…”

Section: Introductionmentioning

confidence: 99%

Electrochemical and Chemical Oxidation of [Pt₂(μ-pyrophosphite)₄]⁴⁻ Revisited: Characterization of a Nitrosyl Derivative, [Pt₂(μ-pyrophosphite)₄(NO)]³⁻

et al. 2009

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Electrochemical studies of the salts [cat](4)[Pt(2)(mu-pop)(4)] (cat(+) = Bu(4)N(+) or PPN(+) [Ph(3)P=N=PPh(3)](+); pop = pyrophosphite, [P(2)O(5)H(2)](2-)) have been carried out in dichloromethane. In agreement with published studies of K(4)[Pt(2)(mu-pop)(4)] in water and [Ph(4)As](4)[Pt(2)(mu-pop)(4)] in acetonitrile, the [Pt(2)(mu-pop)(4)](4-) anion is found to undergo an initial one-electron oxidation under conditions of cyclic voltammetry to a short-lived trianion, [Pt(2)(mu-pop)(4)](3-). However, in the more weakly coordinating solvent dichloromethane, [Pt(2)(mu-pop)(4)](3-) appears to undergo oligomerization instead of solvent-induced disproportionation; thus the overall process remains a one-electron reaction rather than an overall two-electron oxidative addition process, even under long time-scale, bulk electrolysis conditions. Chemical oxidation of [cat](4)[Pt(2)(mu-pop)(4)] with [NO][BF(4)] or AgBF(4) gives mainly a dark, insoluble, ill-defined solid that appears to contain Pt(III) according to X-ray photoelectron spectroscopy (XPS). In the case of [NO][BF(4)], a second reaction product, an orange solid, has been identified as a nitrosyl complex, [cat](3)[Pt(2)(mu-pop)(4)(NO)]. The X-ray structure of the PPN(+) salt shows the anion to consist of the usual lantern-shaped Pt(2)(mu-pop)(4) framework with an unusually large Pt-Pt separation [2.8375(6) A]; one of the platinum atoms carries a bent nitrosyl group [r(N-O) = 1.111(15) A; angle(Pt-N-O) = 118.1(12) degrees] occupying an axial position. The nitrosyl group migrates rapidly on the (31)P NMR time-scale between the metal atoms at room temperature but the motion is slow enough at 183 K that the expected two pairs of inequivalent phosphorus nuclei can be observed. The X-ray photoelectron (XP) spectrum of the nitrosyl-containing anion confirms the presence of two inequivalent platinum atoms whose 4f(7/2) binding energies are in the ranges expected for Pt(II) and Pt(III); an alternative interpretation is that the second platinum atom has a formal oxidation number of +4 and that its binding energy is modified by the strongly sigma-donating NO(-) ligand. Reduction of [Pt(2)(mu-pop)(4)X(2)](4-) (X = Cl, Br, I) in dichloromethane corresponds to a chemically reversible, electrochemically irreversible two-electron process involving loss of halide and formation of [Pt(2)(mu-pop)(4)](4-), as is the case in more strongly coordinating solvents.

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“…Gaussian resolved four peaks have been found at 335.65, 340.91, 338.1, and 343.3 for palladium different chemical environment, which corresponds to Pd(0) and Pd(II), respectively. [ 37 ] Although the total amount of Pd(II) on the silica should not obtain from the XPS result because of the information depth, [ 38 ] after calculated according to ICP-AES, the ratio of Pd(0)/Pd(II) can be obtained with 1/1 and the loading Pd(II) amount is 0.07 mmol g − 1 of catalysts.…”

Section: Supported Catalystsmentioning

confidence: 99%

“…The Cl 2p 3/2 band in supported catalysts appears at 200.1 eV, which can be attributed to the Cl atom bonded to palladium complex. [ 37 ] …”

Section: Supported Catalystsmentioning

confidence: 99%

Preparation of Nanosilica/Polynorbornene Nanocomposite by Covalently Immobilized Silica‐Supported Acetylacetonate Palladium(II) Dichloride Catalyst

Yuan

Chen

et al. 2011

Macro Chemistry & Physics

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Covalently immobilized silica-supported acetylacetonate dichloride palladium(II) precatalyst is prepared by the reaction of silica particles grafted acetylacetonate ligand further exchange with [Et 4 N] 2 PdCl 4 . The silica-supported catalyst is used in slurry polymerizations of norbornene (NB) to afford a highly productive NB addition polymerization system in combination with B(C 6 F 5 ) 3 cocatalyst. It exhibits productivity of 84 kg of PNB (mol Pd) − 1 h − 1 at the initial activity, and the catalyst deactivation kinetics in the early stage of polymerization are fi tted well by the fi rst-order deactivation kinetics. The obtained vinyl-type polynorbornene is confi rmed to be nanosilica hybrid PNB nanocomposite by SEM, TEM with an energy dispersive spectrometer, TGA, and XRD. SiO2 OSiMe3 O OSiMe3 O Si OEt O O Pd Cl Cl

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Photoelectron spectroscopy of coordination compounds. III. Comparison of platinum(II) and platinum(IV) compounds

Cited by 40 publications

References 0 publications

A Piece of the Picture—Misunderstanding of Chemical Concepts

A Piece of the Picture—Misunderstanding of Chemical Concepts

Electrochemical and Chemical Oxidation of [Pt₂(μ-pyrophosphite)₄]⁴⁻ Revisited: Characterization of a Nitrosyl Derivative, [Pt₂(μ-pyrophosphite)₄(NO)]³⁻

Preparation of Nanosilica/Polynorbornene Nanocomposite by Covalently Immobilized Silica‐Supported Acetylacetonate Palladium(II) Dichloride Catalyst

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Photoelectron spectroscopy of coordination compounds. III. Comparison of platinum(II) and platinum(IV) compounds

Cited by 40 publications

References 0 publications

A Piece of the Picture—Misunderstanding of Chemical Concepts

A Piece of the Picture—Misunderstanding of Chemical Concepts

Electrochemical and Chemical Oxidation of [Pt2(μ-pyrophosphite)4]4− Revisited: Characterization of a Nitrosyl Derivative, [Pt2(μ-pyrophosphite)4(NO)]3−

Preparation of Nanosilica/Polynorbornene Nanocomposite by Covalently Immobilized Silica‐Supported Acetylacetonate Palladium(II) Dichloride Catalyst

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Electrochemical and Chemical Oxidation of [Pt₂(μ-pyrophosphite)₄]⁴⁻ Revisited: Characterization of a Nitrosyl Derivative, [Pt₂(μ-pyrophosphite)₄(NO)]³⁻