Triruthenium dodecacarbonyl is the

chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one ele ...

with the formula Ru₃(CO)₁₂. Classified as

metal carbonyl cluster In chemistry, a metal carbonyl cluster is a compound that contains two or more metals linked in part by metal-metal bonds and containing carbon monoxide (CO) as the exclusive or predominant ligand. The area is a subfield of metal carbonyl chemistr ...

, it is a dark orange-colored solid that is soluble in nonpolar organic solvents. The compound serves as a precursor to other

organoruthenium compound Organoruthenium chemistry is the chemistry of organometallic compounds containing a carbon to ruthenium chemical bond. Several organoruthenium catalysts are of commercial interest and organoruthenium compounds have been considered for cancer thera ...

Structure and synthesis

The cluster has ''D_3h'' symmetry, consisting of an

equilateral triangle In geometry, an equilateral triangle is a triangle in which all three sides have the same length. In the familiar Euclidean geometry, an equilateral triangle is also equiangular; that is, all three internal angles are also congruent to each oth ...

of Ru atoms, each of which bears two axial and two equatorial CO ligands. Os₃(CO)₁₂ has the same structure, whereas Fe₃(CO)₁₂ is different, with two bridging CO ligands, resulting in C_2v symmetry. Ru₃(CO)₁₂ is prepared by treating solutions of

ruthenium trichloride Ruthenium(III) chloride is the chemical compound with the formula RuCl3. "Ruthenium(III) chloride" more commonly refers to the hydrate RuCl3·''x''H2O. Both the anhydrous and hydrated species are dark brown or black solids. The hydrate, with a va ...

with

carbon monoxide Carbon monoxide ( chemical formula CO) is a colorless, poisonous, odorless, tasteless, flammable gas that is slightly less dense than air. Carbon monoxide consists of one carbon atom and one oxygen atom connected by a triple bond. It is the si ...

in the presence of a base.

Dichlororuthenium tricarbonyl dimer Dichlororuthenium tricarbonyl dimer is an organoruthenium compound with the formula uCl2(CO)3sub>2. A yellow solid, the molecule features a pair of octahedral Ru centers bridged by a pair of chloride ligands. The complex is a common starting ...

is an intermediate. The stoichiometry of the reaction is uncertain, one possibility being the following: :6 RuCl₃ + 33 CO + 18 CH₃OH → 2 Ru₃(CO)₁₂ + 9 CO(OCH₃)₂ + 18 HCl

Reactions

The chemical properties of Ru₃(CO)₁₂ have been widely studied, and the cluster has been converted to hundreds of derivatives. High pressures of CO convert the cluster to the monomeric

ruthenium pentacarbonyl Ruthenium pentacarbonyl is the organoruthenium compound with the formula Ru(CO)5. It is a colorless, light-sensitive liquid that readily decarbonylates upon standing at room temperature. It is of academic interest as an intermediate for the sy ...

, which reverts to the parent cluster upon standing. :Ru₃(CO)₁₂ + 3 CO 3 Ru(CO)₅ K_eq = 3.3 x 10⁻⁷ mol dm⁻³ at room temperature The instability of Ru(CO)₅ contrasts with the robustness of the corresponding Fe(CO)₅. The

condensation Condensation is the change of the state of matter from the gas phase into the liquid phase, and is the reverse of vaporization. The word most often refers to the water cycle. It can also be defined as the change in the state of water vapor ...

of Ru(CO)₅ into Ru₃(CO)₁₂ proceeds via initial, rate-limiting loss of CO to give the unstable, coordinatively unsaturated species Ru(CO)₄. This tetracarbonyl binds Ru(CO)₅, initiating the condensation. Upon warming under a pressure of

hydrogen Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic ...

, Ru₃(CO)₁₂ converts to the

tetrahedral In geometry, a tetrahedron (plural: tetrahedra or tetrahedrons), also known as a triangular pyramid, is a polyhedron composed of four triangular faces, six straight edges, and four vertex corners. The tetrahedron is the simplest of all the ...

cluster H₄Ru₄(CO)₁₂. Ru₃(CO)₁₂ undergoes substitution reactions with Lewis bases: :Ru₃(CO)₁₂ + ''n'' L → Ru₃(CO)_12-''n''L_''n'' + ''n'' CO (''n'' = 1, 2, or 3) where L is a tertiary

phosphine Phosphine ( IUPAC name: phosphane) is a colorless, flammable, highly toxic compound with the chemical formula , classed as a pnictogen hydride. Pure phosphine is odorless, but technical grade samples have a highly unpleasant odor like rotti ...

or an

isocyanide An isocyanide (also called isonitrile or carbylamine) is an organic compound with the functional group –. It is the isomer of the related nitrile (–C≡N), hence the prefix is ''isocyano''.IUPAC Goldboo''isocyanides''/ref> The organic fra ...

. It forms complexes with

acenaphthylene Acenaphthylene, a polycyclic aromatic hydrocarbon is an ortho- and peri-fused tricyclic hydrocarbon. The molecule resembles naphthalene with positions 1 and 8 connected by a -CH=CH- unit. It is a yellow solid. Unlike many polycyclic aromatic hyd ...

Ru-carbido clusters

At high temperatures, Ru₃(CO)₁₂ converts to a series of clusters that contain interstitial carbido ligands. These include Ru₆C(CO)₁₇ and Ru₅C(CO)₁₅. Anionic carbido clusters are also known, including u₅C(CO)₁₄sup>2− and the bioctahedral cluster u₁₀C₂(CO)₂₄sup>2−.Nicholls, J. N.; Vargas, M. D. "Carbido-Carbonyl Ruthenium Cluster Complexes" Inorganic Syntheses, 1989, volume 26, pages 280-85. Ru₃(CO)₁₂ -derived carbido compounds have been used to synthesize nanoparticles for catalysis. These particles consist of 6-7 atoms and thus are all surface, resulting in extraordinary activity.

References

{{Ruthenium compounds Organoruthenium compounds Carbonyl complexes Chemical compounds containing metal–metal bonds