A COMPARATIVE-STUDY OF THE REACTIVITY OF SOME DINUCLEAR ALKANEDIYL COMPLEXES OF THE TYPE [L(CO)2M(CH2)NM(CO)2L] (WHERE M=FE AND L=ETA-5-C5H5, ETA-5-C5H4ME OR ETA-5-C5ME5 AND N=4-6 OR M=RU AND L= ETA-5-C5H5 AND N=5)

Some reactions of the mu-(alpha,omega)alkanediyl complexes of the type [L(CO)2M(CH2)n M(CO)2L] with both nucleophiles and electrophiles have been investigated. Reaction of the di-iron compounds [L(CO)2Fe(CH2)nFe(CO)2L] with neutral donor ligands (D) gives [LD(CO)FeC(O)(CH2)nC(O)Fe(CO)DL] [where L = eta-5-C5H4Me (Cp'), D = PMePh2, PMe2Ph or t-BuNC and n = 4 or 6; L = eta-5-C5Me5 (Cp*), D = CO and n = 4]. Reactions of the di-iron compounds with SO2 yield disulphinato derivatives [L(CO)2 Fe(SO2)(CH2)4(SO2)Fe(CO)2L] (L = Cp' or Cp*). Halogens cause cleavage of the M-C bonds to give LM(CO)2X and X(CH2)(n)X (M = Fe, L = Cp' or Cp*, X = Br or I and n = 4-6; M = Ru, L = Cp, X = Br or I and n = 5). Reactions of the di-iron or diruthenium compounds with Ph3CPF6 yield the cationic alkene, alkyl complexes [L(CO)2M{mu-(C(n)H2n-1)}M(CO)2L]PF6 (M = Fe, L = Cp or Cp* and n = 4 or 6; M = Ru, L = Cp and n = 5). The diruthenium complex [Cp(CO)2Ru(CH2)5Ru(CO)2Cp] reacts with ligands (D) to give the monosubstituted monoacyl compound [Cp(CO)2Ru(CH2)5C(O)Ru(CO)DCp] and the disubstituted diacyl compound [CpD(CO)RuC(O)(CH2)5C(O)Ru(CO)DCp] (D = PPh3, PMePh2 or PMe2Ph). The reactions are compared with those found for the di-iron compounds [Cp(CO)2Fe(CH2)nFe(CO)2Cp] as well as mononuclear alkyl analogues.