14N, 17O, 103Rh NMR Studies of Rh(III) State in Diluted Nitric Acid Solutions
Russian Journal of Coordination Chemistry
, E-ISSN: 1608-3318
Boreskov Institute of Catalysis, Siberian Division, Russian Academy of Sciences, pr. Akademika Lavrent’eva 5, Novosibirsk, 630090 Russia
International Science and Technology Center
The state of rhodium(III) in nitric acid solutions diluted with 3M HNO3 or water was studied by 14N, 17O, and 103Rh NMR methods. The 103Rh NMR chemical shifts significantly depend on the ionic background of the solution. Concentrated nitric acid solutions (cRh = 0.5–1 mol/l) diluted 100 to 200 times retain the polynuclear Rh(III) forms with double (μ-NO3, μ-OH) bridges. The predominant form in the diluted solutions is a dimer.