Abstract: The transformations of Pt complex species in concentrated NaOH solutions (1−12 M) of Na2[PtCl6] were studied with a combination of methods, including 195Pt nuclear magnetic resonance, ultraviolet−visible, and Raman spectroscopy. The two-step process was observed under the following conditions: (1) formation of the [Pt(OH)5Cl]2− anion that proceeds relatively fast even at room temperature and (2) further slow substitution of the last chlorido ligand with the formation of the [Pt(OH)6]2− anion. Overall, it was determined that the [PtCl6]2− to [Pt(OH)6]2− transformation (especially the first stage) is greatly accelerated under blue light (455 nm) irradiation. The structures of [Pt(OH)Cl5]2− and [Pt(OH)5Cl]2− were determined using the single-crystal X-ray diffraction data of the corresponding salts isolated for the first time. Analysis of the [Pt(OH)Cl5]2− reactivity showed that under analogous conditions, its hydrolysis proceeds 2 orders of magnitude slower than that of [PtCl6]2−, indicating that the formation of [Pt(OH)5Cl]2− from [PtCl6]2− (stage 1) does not follow a simple sequential substitution pattern. A model for [Pt(OH)5Cl]2− anion formation that includes the competing reaction of direct Cl ligand substitution and the self-catalyzed secondorder reaction caused by a redox process is proposed. The influence of Pt speciation in alkaline solutions on the reductive behavior is shown, illustrating its impact on the preparation of Pt nanoparticles.

Cite: Vasilchenko D. , Berdyugin S. , Komarov V. , Sheven D. , Kolesov B. , Filatov E. , Tkachev S.
Hydrolysis of [PtCl6]2– in Concentrated NaOH Solutions
Inorganic Chemistry. 2022. V.61. N15. P.5926-5942. DOI: 10.1021/acs.inorgchem.2c00414 WOS Scopus РИНЦ OpenAlex

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Submitted:

Feb 7, 2022

Identifiers:

Web of science:	WOS:000791949700026
Scopus:	2-s2.0-85128487758
Elibrary:	48430468
OpenAlex:	W4223490484

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Web of science	8
Scopus	8
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