The chemistry of polynuclear compounds. Part XXIV. Some cationic carbonyl derivatives of ruthenium

Abstract

The complex HRu₃(CO)₁₀SEt (1) readily dissolves in concentrated sulphuric acid (98%) at room temperature to give the protonated species H₂Ru₃(CO)₁₀SEt⁺(2). When this solution is heated at 100 °C for 15–20 min. carbon monoxide is evolved and the trihydrido-cation H₃Ru₃(CO)₉S⁺(3) is produced. On dilution of this solution with water the neutral complex H₂Ru₃(CO)₉S (4) is precipitated. The composition of this complex has been confirmed by proton magnetic resonance and mass spectroscopy and the most likely structure of (4) is considered to be a tetrahedron of three rutheniums and one sulphur atom with three terminal CO group per ruthenium and two H ligands occupying regions between the metal atoms. Similar experiments with D₂SO₄ revealed that neither (1) nor (3) undergo proton exchange in concentrated H₂SO₄ but do in more dilute solutions.