Mono- and bis-(acetylacetonato) complexes of arene-ruthenium(II) and arene-osmium(II): Variation of the binding mode of η1-acetylacetonate with the nature of the arene

Article abstract of DOI:10.1139/v01-076

The mono(acetylacetonato) complexes [MCl(O,O′-acac)(η⁶-arene)] (M = Ru, Os, arene = C₆H₆, 1,3,5-C₆H₃Me₃, C₆Me₆; M = Os, arene = 1,2-C₆H₄Me₂, 1,2,3-C₆H₃Me₃), which are formed from [MCl₂(η⁶-arene)]₂ and thallium or sodium acetylacetonate, react with thallium acetylacetonate to give bis(acetylacetonato) complexes [M(O,O′-acac)(η¹-acac)(η⁶-arene)]. The η¹-acac ligand is bound through the γ-carbon atom for M = Ru, Os, arene = C₆H₆; M = Os, arene = 1,2-C₆H₄Me₂, 1,2,3-C₆H₃Me₃ and through a keto-oxygen atom for M = Ru, Os, arene = 1,3,5-C₆H₃Me₃, C₆Me₆, the difference being attributed to a combination of steric and electronic effects. Cationic ruthenium(II) derivatives [Ru(L)(O,O′-acac)(η⁶-arene]⁺ (arene = C₆H₆, 1,3,5-C₆H₃Me₃, C₆Me₆; L = DMSO, MeCN, py, PPh₃) and [Ru(CO)(O,O′-acac)(η⁶-arene]⁺ (arene = 1,3,5-C₆H₃Me₃,C₆Me₆), and neutral osmium(II) η¹-acetato derivatives [Os(η¹-OAc)(O,O′-acac)(η⁶-arene)] (arene = C₆H₆, 1,2-C₆H₄Me₂, 1,2,3-C₆H₃Me₃, 1,3,5-C₆H₃Me₃, C₆Me₆) are also described. The molecular structures of the following complexes have been determined by X-ray crystallography: [Os(O,O′-acac)(η¹-C-acac)(η⁶-1,2-C ₆H₄Me₂)], triclinic, space group P1 (No. 2), a = 9.922(2), b = 9.974(2), and c = 11.001(2) A, α = 68.33(1), β = 64.18(1), and γ = 62.38(1)°, V = 849.0(3) A³, Z = 2; [Os(O,O′-acac)(η¹-O-acac)(η⁶-1,3,5-C ₆H₃Me₃)], monoclinic, space group C2/c (No. 15), a = 16.032(4), b = 11.989(3), and c = 21.562(7) A, β = 108.91(2)°, V = 3921(2) A, Z = 8; [Os(η¹-OAc)(O,O′-acac)(η⁶-C₆H ₆)], triclinic, space group P1 (No. 2), a = 8.368(4), b = 8.402(4), and c = 11.008(4) A, α = 71.68(3), β = 69.35(3), and γ = 69.77(3)°, V = 663.0(6) A³, Z = 2.