Transformations of ferrates(IV,V,VI) in liquids: Mossbauer spectroscopy of frozen solutions

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61988987%3A17310%2F18%3AA1901WM9" target="_blank" >RIV/61988987:17310/18:A1901WM9 - isvavai.cz</a>

Alternative codes found

RIV/61989592:15310/18:73589823

Result on the web

<a href="http://dx.doi.org/10.1039/c8cp05952g" target="_blank" >http://dx.doi.org/10.1039/c8cp05952g</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1039/c8cp05952g" target="_blank" >10.1039/c8cp05952g</a>

Result language

angličtina

Original language name

Transformations of ferrates(IV,V,VI) in liquids: Mossbauer spectroscopy of frozen solutions

Original language description

The kinetics and mechanism of ferrate(IV), (V) and (VI) transformations in water and in polar organic solvents (namely ethanol and tetrahydrofuran) have been investigated by the method of 57Fe Mo ?ssbauer spectroscopy of frozen solutions. Ethanol with a very limited amount of water under an inert atmosphere, significantly slows down the transformation reactions of ferrates(IV and V) and provides direct proof of the existence of intermediate states. Simultaneously, ethanol is oxidized to caboxylates in the close vicinity of the surface of ferrate crystallites as proven by X-ray photoelectron spectroscopy. On the contrary, any transformation of ferrate(VI) in pure ethanol (with a very limited amount of water) was not observed. Mo ?ssbauer spectroscopy of frozen solutions enabled us to experimentally identify and quantify intermediates of ferrate(IV) and ferrate(V) transformations for the first time. Sodium ferrate(IV) in its tetrahedral form, Na4FeO4, undergoes a two-step charge disproportionation to Fe(III) and Fe(VI) via a Fe(V) intermediate without any evolution of oxygen in polar protic and aprotic solvents, specifically 2Fe(IV) - Fe(III) + Fe(V), and Fe(IV) + Fe(V) - Fe(III) + Fe(VI), i.e. in sum 3Fe(IV) - 2Fe(III) + Fe(VI). Ferrate(V) (K3FeO4) transforms to Fe(III) and Fe(VI) without any indication of the Fe(IV) intermediate within the detection limit of the method. In addition to a charge disproportionation reaction proceeding in polar liquids, 3Fe(V) - Fe(III) + 2Fe(VI), a competitive reduction of Fe(V) directly to Fe(III) accompanied by oxygen evolution takes place in water. Oxygen evolution was also measured for ferrate(IV and VI) transformations in water, but to a higher and a smaller extent compared to ferrate(V), respectively. The thermodynamics of the suggested ferrate(IV) and ferrate(V) transformation pathways was examined by DFT calculations.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10301 - Atomic, molecular and chemical physics (physics of atoms and molecules including collision, interaction with radiation, magnetic resonances, Mössbauer effect)

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2018

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Physical Chemistry Chemical Physics

ISSN

1463-9076

e-ISSN

1463-9084

Volume of the periodical

20

Issue of the periodical within the volume

48

Country of publishing house

GB - UNITED KINGDOM

Number of pages

10

Pages from-to

30247-30256

UT code for WoS article

000453231100014

EID of the result in the Scopus database

2-s2.0-85058461054