Ruthenium complexes containing hexamethylbenzene and butadienesulfonyl ligands: Synthesis and reactivity toward CO, nitrogen and phosphine ligands

• Series of (HMB)Ru compounds with butadienesulfonyl ligands were synthesized.
• Addition reactions with σ and π complementary ligands afford a variety of derivatives.
• Reactivity studies in presence of deuterated and no deuterated nitrogen ligands.
• A comparative study of isoelectronic fragments (HMB)RuCl and Cp*MCl (Rh, Ir).

The heterometallic tetranuclear complexes [(HMB)Ru(Cl)2(5-η-CH2CHCRCHSO2)(Li)(THF)]2 [R = H, 3; Me, 4] were synthesised by reaction of [(HMB)Ru(μ-Cl)Cl]2 (1) (HMB = η6-C6Me6) and an excess of [CH2CHCRCHSO2Li] (R = H, Me), whereas mononuclear complexes [(HMB)Ru(Cl)(1,2,5-η-CH2CHCRCHSO2)] (R = H, 7; Me, 8) were obtained when [CH2CHCRCHSO2K] was used. Complex [(HMB)Ru(Cl)2(5-η-CH2CHCHCHSO2)(K)(THF)]2 (5) was spectroscopically detected by 1H and 13C NMR. Solution experiments demonstrated that the above mentioned compounds transform into new ones by simply dissolving or standing in solution. Isolation of the ion pair complex [(HMB)Ru(Cl)(5-η-CH2CHCHCHSO2)(5-η-CH2CHCHCHSO2K)] (9) and subsequent addition of AgBF4 results in the formation of [(HMB)Ru(1,2,5-η-CH2CHCHCHSO2)(5-η-CH2CHCHCHSO2)] (10). Further reactivity of complexes 7 and 8 showed the addition reactions of a variety of ligands such as CO, deuterated and non-deuterated pyridine and acetonitrile, resulting in complexes of the type [(HMB)Ru(Cl)(5-η-CH2CHCRCHSO2)L] [R = H, L = CO, 11; Py, 12, Py-d5, 12D; R = Me, L = Py, 13, Py-d5, 13D; R = H, L = CD3CN, 14D]. Treatment with phosphines afforded the addition products [(HMB)Ru(Cl)(5-η-CH2CHCHCHSO2)L] (L = PMe3, 15; PPh3, 16; PHPh2, 17) and the formation of the dichloride complexes [(HMB)Ru(Cl)2PR3] 15Cl, 16Cl and 17Cl, respectively, as by-products. Compounds 8 and 15 were characterized by single crystal X-ray crystallography. Additionally, a comparative study with isoelectronic and related compounds was undertaken.

Representative examples of hexamethylbenzene ruthenium compounds with butadienesulfonyl and butadienesulfinate ligands were synthesized. The study also includes derivatives with σ and π complementary ligands.Figure optionsDownload as PowerPoint slide