Ruthenium halides

Ruthenium forms the whole range of trihalides but only fluorides in higher states. 

RuF3 can be made by iodine reduction of RuF5. It is obtained as a dark brown powder that contains comer-shared RuF6 octahedra [15]. RuC13 exists in a- and /3-phases  

The o-form has the a-TiCl3 structure with 6-coordinate ruthenium and a rather long Ru-Ru distance (3.46A) compared with the /3-form where 

Black-brown RuBr3 has roughly octahedral coordination of ruthenium (Ru-Br 2.46-2.54 A) with short Ru-Ru contacts (2.73 A) [17]. Black Rul3 has a similar structure. Neither is particularly soluble in water. 

It has a VF4 type puckered sheet structure with 6-coordinated ruthenium four fluorines bridge, two non-bridging ones are trans with the terminal distances shorter as expected (Table 1.1). It is paramagnetic (/xeff = 3.04/xB at room temperature). 

There are no convincing reports of halides in oxidation states below III early reports of Osl and OsI2 seem to result from oxide contaminations. Neither is there OSF3, evidence of the greater stability of the +4 state compared with that of ruthenium. 

Black OsBr3 and OSI3 (/j = 1.8 /uB) are also prepared by thermal methods 

a yellow-brown solid that distills as a viscous liquid, is made by reduction of solutions of OsF5 

Black OsCl4 exists in two forms. A high-temperature form is made by reaction of the elements 

The low-temperature form is made using thionyl chloride as the chlorinating agent. 

Dark grey OSCI3 has the 6-coordinate a-RuCl3 structure 

---

The preparation of carbonylmetals by treating a transition metal halide either with carbon monoxide and zinc, or with iron pentacarbonyl is well-known and smooth. However, a violent eruptive reaction occurs if a methanolic solution of a cobalt halide, a rhodium halide or a ruthenium halide is treated with both zinc and iron pentacarbonyl. 

Ruthenium halides in Me O solution under an atmosphere of hydrogen are known to form complexes of the type [RuX2(Me2SO)4]... 

Reduction of ammonium chlororuthenate with titanous chloride gives a solution containing divalent ruthenium which will absorb ethylene or propylene to give a 1 1 ruthenium-olefin complex which was not isolated (108). Ethylene was previously reported not to form stable complexes on treatment with ruthenium halides (97). 

The strongly chelating dienes bicyclo[2,2,l]hepta-2,5-diene (1) and cyclo-octa-1,5-diene (12) react with ruthenium halides to give stable, diamagnetic complexes of the composition [RuX2(diene)] (X = Cl, Br, I). Note added in proof. 

Ammino-derivatives of Ruthenium Halides—Derivatives of Ruthenium Salts containing a Nitroso-group—Ammino-derivatives of Rhodium Salts— Ammino-derivatives of Palladium Salts. 

The Z or E selectivity may arise from a trans or a cis haloruthenation, depending on the rf-alkyne ruthenium halide complex, more ionic or more covalent species, this equilibrium being displaced by the reaction conditions (Scheme 3). 

This section covers the chemistry of pure halides, aqua-, hydroxo-, oxo- and carbonyl halides. For nitrido and nitrosyl halides see Sections 45.4.6 and 45.4.4.4 respectively. Unlike most other sections of this article, much of the published work on ruthenium halides is pre-1970 and excellent, detailed reviews2,3 have appeared in the literature. Therefore in order to conserve space and avoid undue repetition, only a relatively brief account containing earlier key references and more recent data is presented here. 

A very dangerous fire and moderate explosion hazard when exposed to heat or flame can react vigorously with oxidizing materials. Warning pyrophoric in air. Mixtures with nitrogen oxide explode above 50°C. Violent reaction with zinc + transition metal halides (e.g., cobalt halides, rhodium halides, ruthenium halides). Mixtures with acetic acid + water produce a pyrophoric powder. To fight fire, use water, foam, CO2, dr " chemical. See also CARBONYLS and IRON COMPOUNDS. 

To date, several jt-allylmthenium complexes have been prepared and reported. The representative methods for introducing an allyl group to a ruthenium complex are quite similar to those for other transition metals for example, (1) the reaction of ruthenium halides with allyl Grignard reagents (2) the insertion of conjugated dienes into a hydrido-ruthenium bond and (3) the oxidative addition of several allylic compounds to low-valence ruthenium complexes. 

As the other synthetic method of organoruthenium compounds, the reaction of organolithium compounds or Grignard reagents with metal halides, which is the representative synthetic method of the main group organometallic compounds, is also available [25—28]. For example, organoalkali metal compounds react easily with ruthenium halides to form condensation products as shown in eq. (16.17) [25]. 

As the reaction with organomagnesium compounds, Grignard phenyl reagents react with ruthenium halides to afford phenylruthenium compounds, and the phenylruthenium compounds are heated to afford a benzyne ruthenium as shown in Scheme 16.5 [28]. 

When formaldehyde reacts with rhodium halides, carbonylation proceeds (hydrocarbonylation between formaldehyde and a ruthenium halide as described in Chapter 16 proceeds). A Vaska type rhodium complex is obtained by the reaction with phosphine as shown in eq. (18.7) [17]. 

Grignard reagents also react with inorganic halides to give coupled products. Examples of such halides are cupric chloride, lead chloride, silver bromide, silver cyanide, nickel chloride, palladium chloride, chromic chloride, iron halide, ruthenium halide, and rhodium halide. 

---