ESCA study of Pt(III) and Pt(I) compounds

Catalytically Active Nanocomposites Based on Palladium and Platinum Nanoparticles in Poly(2‐vinylpyridine) Brushes

“…In the Pt 4f 7/2 component peak A shows Pt 2+ and component peak C Pt 4+ ions . Component peak B indicates the complex formation between plati­num ions and the pyridine groups . Here, the nitrogen atom of the pyridine group can act as n‐electron donator, and the aromatic ring is able to support the complex formation by donation of π‐electron density.…”

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

“…The platinum 4f 7/2 binding energy in platinum complexes increases by about 1.1 eV for each unit increase in the formal oxidation state of the metal atoms, although ligand effects in complexes of the same oxidation state can be almost as large. − The XP spectrum of the diplatinum(II) complex [Bu 4 N] 4 [Pt 2 (μ-pop) 4 ] ( 1 ) shows a typical 4f 7/2 /4f 5/2 doublet, the binding energy of the 4f 7/2 peak being 72.0 eV; the spectra of the diplatinum(III) complexes [Bu 4 N] 4 [Pt 2 (μ-pop) 4 X 2 ] ( 2a - c ) are similar, the binding energies of the 4f 7/2 peaks (in eV) being 73.5 (X = Cl), 73.2 (X = Br), and 73.1 (X = I). Although the trend in binding energies is similar, the values are consistently lower by about 1 eV than those reported for the same anions with different cations, namely, K 4 [Pt 2 (μ-pop) 4 ]·2H 2 O ( 1 ) (73.7 eV), K 4 [Pt 2 (μ-pop) 4 Cl 2 ]·2H 2 O ( 2a ) (75.1 eV), K 4 [Pt 2 (μ-pop) 4 Br 2 ] ( 2b ) (74.5 eV), [Ph 4 As] 4 [Pt 2 (μ-pop) 4 I 2 ] ( 2c ) (73.7 eV).…”

“…Although its binding energy is in the range observed for the diplatinum(III) complexes 2a - c , the value does not exclude the assignment of a formal oxidation state of +4 if one allows the possibility of a marked effect on the binding energy of the strongly σ-donating NO − ligand, with its high trans -influence. Binding energies for octahedral platinum(IV) complexes range from 77.8 eV for K 2 PtF 6 to 73.6 eV for K 2 PtI 6 ; − in platinum(II) complexes, successive replacement of the chloride ligands of [PtCl 2 (PEt 3 ) 2 ] by strongly σ-donating methyl groups causes the Pt 4f 7/2 binding energies to fall from 73.3 to 72.8 eV for [PtClMe(PEt 3 ) 2 ] to 72.4 eV for [PtMe 2 (PEt 3 ) 2 ] . Unfortunately, so far as we know, there are no XP measurements on well-defined platinum-nitrosyl complexes available for comparison .…”

“…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.…”