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Rhodium(III) Speciation in Concentrated Nitric Acid Solutions
Author(s) -
Vasilchenko Danila,
Vorob'eva Sofia,
Tkachev Sergey,
Baidina Iraida,
Belyaev Anatoliy,
Korenev Sergey,
Solovyov Leonid,
Vasiliev Alexander
Publication year - 2016
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.201600523
Subject(s) - rhodium , chemistry , nitric acid , denticity , inorganic chemistry , nitrate , salt (chemistry) , metal , nuclear chemistry , medicinal chemistry , catalysis , organic chemistry
The interaction of rhodium(III) aqua ions with nitrate ions in 3–16 m nitric acid solutions has been studied by 103 Rh and 15 N NMR and Raman spectroscopy. The mononuclear complexes [Rh(H 2 O) 6– n (NO 3 ) n ] 3– n ( n = 1–4) were found to be the only form of rhodium(III) existing in the solutions with the metal concentration in the range 0.2–1.3 m . The dynamics of the H 2 O → NO 3 – substitution process was studied at 80 °C. An increase in the average number of nitrate groups bonded to rhodium with increasing concentration of nitric acid was also determined. The fine crystalline salt Rb 4 trans ‐[Rh(H 2 O) 2 (NO 3 ) 4 ][Rh(NO 3 ) 6 ] was obtained by solvothermal concentration of the rhodium nitric acid solution on addition of rubidium nitrate. The structure of the salt was solved by the powder X‐ray diffraction method, with monodentate coordination of nitrato ligands found for both the [Rh(NO 3 ) 6 ] 3– and trans ‐[Rh(H 2 O) 2 (NO 3 ) 4 ] – anions.