Chlor-ruthenates

Ruthenium Sponge results on ignition of ammonium chlor-ruthenate. It readily dissolves in a solution of hydrogen chloride saturated with chlorine yielding halogen derivatives. Hydrobromic acid saturated with bromine likewise effects the solution of ruthenium sponge. 

When heated in fluorine a volatile fluoride is formed, and in chlorine a chloride is obtained, possibly the dichloride, RuC12. Ignition with potassium chloride in a current of chlorine yields potassium chlor-ruthenate, which is soluble in water. 

The alkali chlor-ruthenates are isomorphous with the chlor-platinates, and therefore, by the application of llitscherlich s Law, they must be assumed to contain, like the platinum derivatives, one atom of ruthenium, their generic formula being M,RuC16. Similarly, ruthenium dioxide is isomorphous with cassiterite, SnO,. and with rutile, TiCL. from which it may be concluded that its formula is RuO.,. Analyses of these compounds indicate that the atomic weight of ruthenium is 101-7. 

Of particular interest is Caesium Chlor-ruthenite, Cs,.RuC]6.H20, which Howe4 obtained by the action of hydrochloric acid on ruthenium tetroxide and subsequent addition of caesium chloride to the solution. The salt is precipitated as a dark brown powder, fairly soluble in water and hydrochloric acid, exhibiting the chemical reactions of a trivalent ruthenium salt. Howe also describes an isomeride of this salt, which lie termed, in accordance with Werner s nomenclature, Caesium Aquo-chlor-ruthenate [vide infra). 

Potassium Aquo-chlor-ruthenate, K2Ru(OH2)CI5, results1 on boiling a slightly acidified solution of potassium chlor-ruthenite, K2RuC15, with alcohol as also by heating the hydrated sesquioxide with hydrochloric acid and alcohol. 

Potassium Nitroso-chlor-ruthenate, K2Ru(NO)Cl-, is known (see p. 150). 

Caesium Aquo-chlor-ruthenate, Cs2Ru(OH2)Cl3, is an interesting salt inasmuch as it is isomeric with the first chlor-ruthenite to be discovered, namely, Cs2RuCl5. HaO vide supra). It is obtained 3 as a buff precipitate on adding alcohol to the blue filtrate from electrically reduced solutions of ruthenium trichloride and caesium chloride. On crystallisation, rose-coloured prisms are obtained. These are soluble in water, and may be recrystallised unchanged from aqueous hydrochloric acid. 

On boiling with concentrated hydrochloric acid chlorine is disengaged, csesium chlor-ruthenate remaining behind. Thus ... 

Ruthenium Disulphide, RuSk, is formed by allowing hydrogen sulphide and potassium chlor-ruthenate solution to react at 80° to 90° C. when it is obtained as a black precipitate.6 When dry it explodes violently if warmed in air. 

Ruthenium Trisulphide, RuS, is obtained by passing hydrogen sulphide through an aqueous solution of potassium chlor-ruthenate at 0° C. It is formed as a yellowish brown precipitate. When dry it readily oxidises in air, becoming heated to incandescence for this reason the sulphide is dried in an atmosphere of an inert gas.e... 

The oxidation of alcohols to carbonyl compounds has been studied by several authors and a variety of methods have been used. Papers concerned vith such oxidations are illustrated (Scheme 3.26). Good results have been obtained using pyridinium chlor-ochromate (PCC) adsorbed onto silica gel for the selective oxidation of unsaturated substrates e.g. terpene [135] and furanyl derivatives [136]. Steroidal homoallylic alcohols can be converted to the corresponding 4-ene-3,6-diones using tetrapropylammo-nium per-ruthenate (TPAP) in catalytic amounts [137]. In this case, the oxidising agent is N-methyl morpholine N-oxide (NMO). 

Ruthenium and the Halogens—Chlor-ruthenifces and Chlor-rathenates—Ruthenium and Oxygen—Ruthenites and Ruthenates—Ruthenium and Sulphur— Nitroso Derivatives—Double Nitrites—Ruthenium and Carbon—Rutheno-oyanides—Ruthenium and Silioon. 

---