Behavior of nitrite forms of nitrosylruthenium on extraction and back extraction of heterometalic Ru/Zn complexes with trioctylphosphine oxide

• Published in: Russian journal of inorganic chemistry Vol. 58; no. 8; pp. 994 - 1003
• Main Authors: Kabin, E. V., Emel’yanov, V. A., Torgov, V. G., Tkachev, S. V., Us, T. V., Korda, T. M.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.08.2013
• Subjects: Ambient temperature; Ammonia; Chemistry; Chemistry and Materials Science; Extraction; Hexanes; Inorganic Chemistry; Nitric acid; Oxides; Phases; Physical Chemistry of Solutions; Ruthenium; Ruthenium; Spend Nuclear Fuel; High Level Waste; Topo; Back Extract
• ISSN: 0036-0236; 1531-8613
• DOI: 10.1134/S003602361308010X

The state of ruthenium in conjugated phases upon extraction of trans -[Ru( 15 NO)( 15 NO 2 ) 4 (OH)] 2− complex with tri - n -octylphosphine oxide (TOPO) in the presence of Zn 2+ and subsequent back extraction with H 15 NO 3 and NH 3 (concd.) solutions was studied by 15 N NMR. Binuclear complexes [Ru(NO)(NO 2 ) 5− n (μ-NO 2 ) n −1 (μ-OH)Zn(TOPO) n ] and [Ru(NO)(NO 2 ) 4− n (ONO)(μ-NO 2 ) n −1 (μ-OH)Zn(TOPO) n ], where n = 2, 3, are predominant forms in extract. Kinetic restrictions for ruthenium extraction with TOPO solution in hexane and its back extraction with aqueous solutions of nitric acid and ammonia are eliminated in the absence of direct coordination of extractant to ruthenium. fac -Dinitronitrosyl forms [Ru(NO)(H 2 O) 3 (NO 2 ) 2 ] + , [Ru(NO)(H 2 O) 2 (NO 2 ) 2 (NO 3 )] 0 (3 and 6 M HNO 3 ) and [Ru(NO)(H 2 O)(NO 2 ) 2 (NO 3 ) 2 ] − (6 M HNO 3 ) prevail in nitric acid back extracts. Equilibrium constant at ambient temperature (0.05 ± 0.01) was assessed for the coordination of second nitrate ion to nitrosylruthenium dinitronitrato complex. Complex species [Ru(NO)(NO 2 ) 4 (OH)] 2− and [Ru(NO)(NO 2 ) 3 (ONO)(OH)] 2− prevail in ammonia back extract.