Solutions Containing Pentaammine nitrogen ruthenium II Cation Impure Product

SOLUTIONS CONTAINING PENTAAMMINE (NITROGEN) -RUTHENIUM(II) CATION (IMPURE PRODUCT) 

Ruthenium(III) chloride (2.0 g., 9 mmoles) (free from nitrosyl impurities) is dissolved in water (10 ml.) in a 200-ml. beaker. Hydrazine hydrate (85%, 20 ml.) is added carefully to the well-stirred solution. The initial reaction is exothermic, and large quantities of gas are evolved. The solution is stirred for about 12 hours and filtered by gravity. Because of the vigorous evolution of gas and the highly exothermic nature of the initial reaction, it is not recommended that the scale of the reaction be increased. Chloro complexes such as (NH )2[RuClt] or K2[RuC15H20] may be substituted for ruthenium (III) chloride. 

The solution obtained as a product contains a mixture of hexa-ammineruthenium(II) and pentaammine(nitrogen)ruthenium-(II) ions. 

To the filtered solution, prepared as in Sec. A, is carefully added concentrated hydrochloric add until the pH is 2 (Alkacid 

The product is recrystallized by heating an aqueous slurry (3 g. in 10 ml. of water) to 60°C. and adding concentrated ammonia dropwise until the yellow complex dissolves to give a wine-red solution. The solution is filtered hot and then cooled in an ice bath. To the cold solution concentrated hydrochloric acid is added dropwise to reprecipitate the mustard-yellow pentaamminechlororuthenium(III) chloride. The product is collected by filtration, washed once with 6 M hydrochloric acid, and then quickly washed with water, alcohol, and acetone. Finally it is dried at 78°C. over P208 in vacuo. Yield is 1.1 g., 39%. Anal. Calcd. for CUHuNsRu H, 5.19 N, 23.98 Cl, 36.35. Found H, 5.30 N, 24.53 Cl, 34.84. 

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