Ruthenium
transition metalProperties
| Property | Value |
|---|---|
| Atomic Mass | 101.07 amu |
| Category | transition metal |
| Group | 8 |
| Period | 5 |
| Electron Configuration | 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s1 4d7 |
| Electronegativity | 2.2 (Pauling) |
| Oxidation States | 3, 4, 2, 6, 8 |
| Melting Point | 2607 K (2333.8 °C) |
| Boiling Point | 4423 K (4149.9 °C) |
| Density | 12.45 g/cm³ |
| Discovered By | Karl Ernst Claus (1844) |
About Ruthenium
Ruthenium is a hard, brittle platinum-group metal Karl Ernst Claus isolated from Ural-mountain platinum residues in 1844, naming it Ruthenia for the Latinized name of his native Russia. It's the only 4d transition metal that reaches the +8 oxidation state (in volatile, orange RuO₄, which smells like ozone and explodes above 100 °C), and it spans nine oxidation states from −2 to +8 in characterized compounds. The metal itself stands up to aqua regia at room temperature and most molten alkalis, which is why a percent or two of Ru hardens platinum in fountain-pen nibs and electrical-contact alloys. The catalytic chemistry is where ruthenium really earns its keep: Grubbs catalysts (Ru-benzylidene NHC complexes) made olefin metathesis a routine bench reaction and earned Robert Grubbs half the 2005 Nobel; tris(bipyridyl)ruthenium(II) is the prototypical photoredox photocatalyst; and in dye-sensitized solar cells, Ru-polypyridyl 'N3' and 'N719' dyes set the early efficiency benchmarks.
Fun Fact
Ruthenium-based catalysts earned Robert Grubbs and Richard Schrock a share of the 2005 Nobel Prize in Chemistry for their work on olefin metathesis, a revolutionary reaction that creates and breaks carbon-carbon double bonds.
Common Uses
- Grubbs-generation Ru-NHC catalysts for olefin metathesis in pharma synthesis
- [Ru(bpy)₃]²⁺ photoredox catalysts for visible-light-driven C-H functionalization
- N3/N719 ruthenium-polypyridyl sensitizers in dye-sensitized solar cells
- Hardener for Pt and Pd alloys in fountain-pen nibs and watch escapements
- RuO₂ electrodes in chlor-alkali cells (DSA anodes) for chlorine production
- Thick-film resistor pastes containing RuO₂ for surface-mount electronics