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

Abstract

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 gamma-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-C6H4Me2)], triclinic, space group P[Formula: see text] (No. 2), a = 9.922(2), b = 9.974(2), and c = 11.001(2) Å, α = 68.33(1), β = 64.18(1), and γ = 62.38(1)°, V = 849.0(3) Å3, Z = 2; [Os(O,O'-acac)(η1-O-acac)(η6-1,3,5-C6H3Me3)], monoclinic, space group C2/c (No. 15), a = 16.032(4), b = 11.989(3), and c = 21.562(7) Å, β= 108.91(2)°, V = 3921(2) Å, Z = 8; [Os(η1-OAc)(O,O'-acac)(η6-C6H6)], triclinic, space group P[Formula: see text] (No. 2), a = 8.368(4), b = 8.402(4), and c = 11.008(4) Å, α = 71.68(3), β = 69.35(3), and γ = 69.77(3)°, V = 663.0(6) Å3, Z = 2.Key words: arene-ruthenium, arene-osmium, acetylacetone, crystal structures.