Comparative reactivity studies of dppf-containing CpRu II and (C 6Me 6)Ru II complexes towards different donor ligands (dppf=1,1 ′-bis(diphenylphosphino)ferrocene)

Abstract

[CpRu(dppf)Cl] (Cp=η 5-C 5H 5) ( 1) and [(HMB)Ru(dppf)Cl]PF 6 ((HMB)=η 6-C 6Me 6) ( 3) react with different donor ligands to give rise to N-, P- and S-bonded complexes. The stoichiometric reactions of 1 and 3 with NaNCS give the mononuclear complexes [CpRu(dppf)(NCS)] ( 2) and [(HMB)Ru(dppf)(NCS)]PF 6 ( 4), respectively, in yields above 80%, while 3 also gives a dppf-bridged diruthenium complex [(HMB)Ru(NCS) 2] 2(μ-dppf) ( 5) in 67% yield from reaction with four molar equivalents of NaNCS. Compound 5 is also obtained in 70% yield from the reaction of 4 with excess NaNCS. With CH 3CN in the presence of salts, both 1 and 3 give their analogous solvento derivatives [CpRu(dppf)(CH 3CN)]BPh 4 ( 6) and [(HMB)Ru(dppf)(CH 3CN)] (PF 6) 2 ( 7). With phosphines, the reaction of 1 gives chloro-displaced complexes [(CpRu(dppf)L]PF 6 (L =PMe 3 ( 8), PMe 2Ph( 9)), whereas the reaction of 3 with PMe 2Ph leads to substitution of dppf, giving [(HMB)Ru(PMe 2Ph) 2Cl] PF 6 ( 10). The reaction of 1 with NaS 2CNEt 2 gives a dinuclear dppf-bridged complex [{CpRu(S 2CNEt 2)} 2(μ-dppf)] ( 11), whereas that of 3 results in loss of the HMB ligand giving a mononuclear complex [Ru(dppf)(S 2CNEt 2) 2] ( 12). With elemental sulfur S 8, 1 is oxidized to give a dinuclear CpRu III dppf-chelated complex [{CpRu(dppf)} 2(μ-S 2)](BPh 4)Cl ( 13), whereas 3 undergoes oxidation at the ligand, giving a dppf-displaced complex [(HMB)Ru(CH 3CN) 2Cl]PF 6 ( 14) and free dppfS 2. The structures of 1, 2, 5– 9, 11, 13 and 14 were established by X-ray single crystal diffraction analyses. Of these, 5 and 11 both contain a dppf-bridge between Ru II centers, while 13 is a dinuclear CpRu III disulfide-bridged complex; all the others are mononuclear. All complexes obtained were also spectroscopically characterized.