Cluster chemistry. Part 31. An [Ru3(CO)12] derivative with an [Fe3(CO)12]-like structure: preparation and X-ray structure of [Ru3(µ-CO)2(CO)6{PPh(OMe)2}4]

Abstract

An X-ray structural determination of [Ru₃(CO)₈{PPh(OMe)₂}₄] shows this complex to be the first example of an [Ru₃(CO)₁₂] derivative with the [Fe₃(CO)₁₂] structure. The three Ru atoms form an isosceles triangle, the shorter edge [2.797(1)Å] of which is asymmetrically bridged by two CO ligands [Ru(1)–C 2.057(8), 2.399(8); Ru(2)–C 2.068(8), 2.389(7)Å; Ru(1)–C–O 150.7(6), 132.5(6); Ru(2)–C–O 131.8(6), 150.4(6)°]; these two Ru atoms are each bonded to an equatorial PPh(OMe)₂ ligand [Ru–P 2.277(2) and 2.281(2)Å]. The unique Ru carries two equatorial PPh(OMe)₂ ligands [Ru–P 2.265(2) and 2.270(2)Å], and forms two longer Ru–Ru bonds [2.879(1)Å]. The occurrence of [Fe₃(CO)₁₂]-type structures is related to the volume of the peripheral-atom polyhedron.