Ruthenium tetrachloride

Ruthenium(IV) tetrachloride is volatile inorganic compound of ruthenium and chlorine with the formula RuCl4.

Synthesis
Synthesis of ruthenium(IV) tetrachloride is formed by the action of chlorine gas on ruthenium(III) chloride at 750 °C:
 * RuCl3 + 0.5Cl2 -> RuCl4

The RuCl4 is collected on a liquefied air cooled condenser and decomposes above -30 °C. The reaction was determined to have the following thermodynamic properties:
 * ΔH°298 = 36.6 kcal/mol (enthalpy)
 * ΔS°298 = 32.8 entropy units (entropy change)
 * ΔC°p = -6.6 cal/mol degree (change in heat capacity at constant pressure)
 * S°298 = 99.3 entropy units

The degree signs indicate standard state.

Properties
Ruthenium(IV) tetrachloride decomposes above -30 °C:
 * RuCl4 -> RuCl3 + 0.5Cl2