Exothermal Effects in the Thermal Decomposition of [IrCl6]2--Containing Salts with [M(NH3)5Cl]2+ Cations: [M(NH3)5Cl][IrCl6] (M = Co, Cr, Ru, Rh, Ir)
Научная публикация
| Общее |
Язык:
Английский,
Жанр:
Статья (Full article),
Статус опубликования:
Опубликована,
Оригинальность:
Оригинальная
|
| Журнал |
New Journal of Chemistry
ISSN: 1144-0546
, E-ISSN: 1369-9261
|
| Вых. Данные |
Год: 2018,
Том: 42,
Номер: 3,
Страницы: 1762-1770
Страниц
: 9
DOI:
10.1039/c7nj04035k
|
| Ключевые слова |
X-RAY-DIFFRACTION; CRYSTAL-STRUCTURE; OXIDATION-STATE; THERMOLYSIS; COMPLEXES; PLATINUM; PRODUCTS; IFEFFIT; XANES; RE |
| Авторы |
Martynova S.A.
1,2
,
Plyusnin P.E.
1,2
,
Asanova T.I.
1
,
Asanov I.P.
1
,
Pishchur D.P.
1
,
Korenev S.V.
1,2
,
Kosheev S.V.
3
,
Floquet S.
4
,
Cadot E.
4
,
Yusenko K.V.
5,6
|
| Организации |
| 1 |
Nikolaev Institute of Inorganic Chemistry, Lavrentiev ave. 3, 630090 Novosibirsk, Russia
|
| 2 |
Novosibirsk State University, Pirogova str. 2, 630090 Novosibirsk, Russia
|
| 3 |
Novosibirsk, Boreskov Institute of Catalysis, 630090 Novosibirsk, Russia
|
| 4 |
Université de Versailles Saint-Quentin, Institut Lavoisier de Versailles (ILV), France
|
| 5 |
College of Engineering, Swansea University, Fabian Way, Swansea SA1 8EN, Wales, UK
|
| 6 |
Institute of Solid State Chemistry, Pervomaiskaia Str. 91, 620090 Ekaterinburg, Russia
|
|
Информация о финансировании (1)
|
1
|
Российский научный фонд
|
16-13-10192
|
[M(NH3)5Cl][IrCl6], M = Co, Cr, Ru, Rh, and Ir, were proposed as single-source precursors for bimetallic alloys. Their thermal decomposition in inert and reductive atmospheres below 700 °C results in the formation of nanostructured porous Ir0.5M0.5 alloys. Salts decompose with a significant exothermal effect during the first stage of their thermal breakdown in an inert atmosphere above 200 °C. The exothermal effect gradually decreases in the series: [Co(NH3)5Cl][IrCl6] (1) > [Cr(NH3)5Cl][IrCl6] (2) > [Ru(NH3)5Cl][IrCl6] (3) > [Rh(NH3)5Cl][IrCl6] (4); [Ir(NH3)5Cl][IrCl6] (5) does not exhibit any thermal effects and decomposes at much higher temperatures. To shed light on their thermal decomposition and the nature of the exothermal effect, DSC-EGA, in situ and ex situ IR, Raman, XPS and XAFS studies were performed. A combination of complementary techniques suggests a simultaneous ligand exchange and a reduction of central atoms as key processes. In [Co(NH3)5Cl][IrCl6], Co(iii) and Ir(iv) simultaneously oxidise coordinated ammonia, which can be detected due to a significant exothermal effect and the presence of Co(ii) and Ir(iii) in the intermediate product. The appearance of Ir-N frequencies demonstrates a ligand exchange between cations and the [IrCl6]2- anion. Salts with Cr(iii), Ru(iii), and Rh(iii) show a much lower exothermal effect due to the stability of their oxidation states. Salts with Rh(iii) and Ir(iii) demonstrate a high thermal stability and a low tendency for ligand exchange as well as decomposition with exothermal effects.